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004 ENGE 2013

09:00-09:45 Poster 1

Poster Session /

3

10:00-11:50 ( ) / C308 & 309

12:00-13:00 /

13:00-13:45 Poster 2

/ 304 / 305 / 306 / 307

14:00-14:30 (UNIST) () (GIST) (DGIST)

14:30-15:00 (KAIST) () (KAIST) ()

15:00-15:30 () () () ()

15:30-16:00 Coffee Break

16:00-16:30 () () () ()

16:30-17:00 () (ETRI) () ()

17:00-17:30 (KAIST) (CPRI) (SAIT) (UNIST)

17:30-18:00 Break

18:00-19:30 ( Poster ) / C308 - 310

1. (304)

14:00-14:30 (UNIST)

14:30-15:00 (KAIST)

15:00-15:30 ()

16:00-16:30Scanning Optoelectronic/Thermal Probes

for Nanoscale Energy Conversion Processes ()

16:30-17:00Self Assembled Carbon Nanotube Networks

for High Performance Organic Electronics ()

17:00-17:30 (KAIST)


2. (305)

14:00-14:30Nanoscale 2-dimensional Hybrid Structure of Graphene/h-BN: Synthesis,

Properties, and Growth Mechanism ()

14:30-15:00 Graphene Application towards Electronic Devices ()

15:00-15:30Nanocrystalline-InZnO Semiconductor Photo-Transistor for Interactive Display

Applications ()

16:00-16:30 Materials and Process Aspect of Cross-point ReRAM ()

16:30-17:00 (ETRI)

17:00-17:30 Functionalized Graphene Flakes for Electronic Application (CPRI)

3. (306)

14:00-14:30Improved Performance of InGaN/GaN MQW Light-Emitting Diodes

by Surface Plasmon (GIST)

14:30-15:003D Nanostructured, Stretchable Electrodes Made

from Proximity field nanoPatterning (KAIST)

15:00-15:30 Large-area Nano-Electronics and Lithography using Nanowire Printing ()

16:00-16:30 Manipulation of Light for Autostereoscopic 3D Displays

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16:30-17:00 Stability of Electrical Doping in Organic Semiconductors ()

17:00-17:30 High Mobility Thin Film Transistors based on Zinc Oxynitride Semiconductors (SAIT)

4. (307)

14:00-14:30 Ab-Initio DFT Discovery of High Functional Catalysts for Fuel Cell Application (DGIST)

14:30-15:00Thermally Driven Solid Solution Nano-sized LixFePO4 and Their Chemical

Properties ()

15:00-15:30 Buffer Phase in the Si-based Anode Materials for Li-ion Battery ()

16:00-16:30Important Physical Factors Determining the Activity of Catalysts for Li-O2 Battery

Applications ()

16:30-17:00 Development of NASICON Li3V2(PO4)3 Material for Lithium Battery ()

17:00-17:30 (UNIST)

006 ENGE 2013

1. Energy

A. Devices and Materials for Energy Harvesting and Storage

B. Novel Fuel Cell

C. Lithium and Advanced Battery Materials

D. Photovoltaic Science

E. Thermoelectric Materials and Devices

F. First Principles Design of Electrode Materials

2. Information Display

A. Flexible Displays and Printed Electronics

B. Thin-Film Encapsulation for AMOLED

C. Flexible Electrode Materials and Ag Nano Wires

D. LED Materials and Devices

E. OLED Materials and Devices

F. Oxide TFT Materials and Devices

G. First Principles Analysis of TFT Materials

3. Nano Engineering

A. Quantum Dots, Nanowires and Other Nanoscale Materials

B. Top Down & Bottom Up Nanopatterning/Nanofabrication

C. Carbon Nanomaterials

D. Nanoscale Devices and Structures

E. Multi-Scailing Computation of Nanomaterials

4. Electronic Materials and Processing

A. Non-Volatile Memory Materials and Processes

B. Advanced Packaging and Interconnection

C. Sensor

D. Oxide Semiconductor

E. Magnetism and Magnetic Materials

F. Computation of Electronic Materials


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016 ENGE 2013

Invited Speech

Scanning Optoelectronic/Thermal Probes for Nanoscale Energy Conversion Processes

Ji Ho Sung1,3, Hoseok Heo1,3, Inchan Hwang1,2, Donghun Lee1,2, Kibum Kang1, Moon-Ho Jo1,2

1Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS)

2Department of Materials Science and Engineering

3Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH)

The scanning photocurrent/voltage imaging technique provides spatially and spectrally resolved local information of light-

matter interaction at the various nanostructures. In this talk, we discuss the recent research efforts of our laboratory to

investigate photon energy conversion/transport processes in several individual nanostructures without ensemble average,

including semiconductor nanowire photodetectors/optical modulators, single-domain ferroelectric photovoltaic switches and

monolayer-chalcogenide thermoelectric cells, where the unique size effects in the each responsible physical process at

the nanometer scales commonly manifest themselves. Therein, the defining characteristic of such energy conversion and

transport are visualized as direct evidence in a spatially and spectrally resolved manner. We argue that our experimental

technique hold general implication for the design rules of the nanoscale energy conversion vehicles.

References

[1] "Diameter-dependent internal gain in intrinsic Ge nanowires", Nano Letters 10, 1025 (2010).

[2] "On-nanowire band-graded Si:Ge photodetectors", Advanced Materials 23, 1025 (2011)

[3] "Large electroabsorption susceptability mediated by internal photoconductive gain in Ge nanowires", Nano Letters 12, 5913 (2011).

[4] "Spatially resolved photodetection in leaky ferroelectric BiFeO3", Advanced Materials 24, OP49 (2012).

[5] "Single ferroelectric-domain photovoltaic switching based on lateral BiFeO3 cells", NPG Asia Materials, 5, e38 (2013)

[6] "Monolayer Chalcogenides Photothermoelectrics", Submitted (2013)

Professor Moon-Ho Jo

Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS)


Invited Speech

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[1] Nature, 462, 1039, (2009); Nature Nanotechnology, 7, 438 (2012); Nano Lett. 13, 2809 (2013).

[2] MRS Bulletin, Vol. 37, Issue 2, 144 (2012); Advanced Functional Materials, 21, 2806 (2011); Organic Electronics, 14, 2087

(2013); IEEE Electron. Device Lett. 34, 51 (2013).



Invited Speech

Self Assembled Carbon Nanotube Networks for High Performance Organic Electronics

Cheolmin Park, Sung Hwan Cho, Seong Soon Jo, Ihn Hwang

Department of Materials Science and Engineering, Yonsei University

Networks of carbon nanotubes (CNTs) have been of great interest for exploiting their novel electronic properties. We

have recently discovered an efficient route for fabricating CNTs networks with their tunable electronic properties, based

on (1) the efficient dispersion of CNTs with a self assembled block copolymer in solution, (2) the control of the number of

nanotubes by centrifugation and (3) the individually networked deposition of CNTs embedded in the block copolymer on

a target substrate. In this presentation, various novel organic electronic devices are introduced based on the networked

carbon nanotubes including FET, electroluminescent device, near IR detector and non-volatile memory. A nanotube network

has been employed as a semi-conducting channel layer of a reliable FET with high On/Off current ratio of approximately

106 which arises from Schottky barriers evolved between the individual m- and s-SWNTs in the network. In addition, a

mechanically rubbed transparent network was successfully introduced to a conventional TN type LC cell as an alignment

layer, giving rise to superfast switching of the TN LC molecules. Furthermore, a nanocomposite of networked CNTs and a

fluorescent polymer turned out an efficient field induced electroluminescent layer under alternating current (AC) as a potential

candidate for next generation displays and lightings. We demonstrate a high-performance field-induced electroluminescence

(FEL) device consisting of four stacked layers: a top metal electrode/thin solution-processed nanocomposite film of CNTs

and a fluorescent polymer/insulator/transparent bottom electrode working under AC electric field. The material design rules

of our FELs are much simpler than conventional light emitting diodes because there is no need to ensure energy band gap

alignment between layers or to control carrier injection and transport, resulting in a very cost-effective device capable of full

color emission.


018 ENGE 2013

Invited Speech

Nanoscale 2-dimensional Hybrid Structure of Graphene/h-BN: Synthesis, Properties, and Growth Mechanism

Sung Kyu Jang1,2, Minwoo Kim1,2, Dorj Odkhuu3, Noejung Park3, Joohyun Lee1,2, Won-Jun Jang4, Se-Jong Kahng4,

Rodney S. Ruoff5, Young Jae Song1,2,6, Sungjoo Lee1,2,7

1SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU)2Center for Human Interface Nanotechnology (HINT), Samsung-SKKU Graphene Center, Sungkyunkwan University (SKKU)

3Interdisciplinary School of Green Energy and Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST)4Department of Physivcs, Korea University

5Department of Mechanical Engineering and the Materials Science and Engineering Program, The University of Texas at Austin6Department of Physics, Sungkyunkwan University (SKKU)

7College of Information and Communication Engineering, Sungkyunkwan University (SKKU)

The Chemical vapor deposition (CVD) of graphene or hexagonal boron nitride (h-BN) films onto transition metal substrates

has been shown to yield large area and high quality films. The sequential CVD growth of graphene on h-BN is of interest as

one might expect the interface to be particularly clean, and achieving sequential growth (without any transfer needed) will

allow exploring the possibility of epitaxial growth, which may be beneficial to device performance. Here we report that large-

scale monolayer graphene can be directly grown on h-BN/Cu-foil by low-pressure CVD method and the direct growth of

graphene on h-BN generates the defect-free and clean graphene/h-BN interface, which is confirmed by STM/STS, Raman,

and electrical carrier transport measurement. We elucidate the CVD growth mechanism of large-area and high quality

graphene on h-BN/Cu by measuring the effects on graphene growth of varying thicknesses of the h-BN layer, along with

KPFM measurement and DFT calculations.

Sungjoo Lee ()

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Invited Speech

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Invited Speech

Graphene Application towards Electronic Devices

Hyun-Jong Chung

Department of Physics, Konkuk University

Graphene has been attracting many intentions for a post-Si material due to its high mobility. Since its gapless band

structure keeps from turning-off the devices in traditional way, until recently, applications for the graphene transistors are

limited to analog amplifiers which does not have to be turned off during the operation. Last year new device structures have

been proposed to solve the issue: graphene barristor [1] and graphene tunneling transistor [2]. Both structures have hetero

junction between graphene and semiconductor or insulator. In this talk, reviewed will be the research on graphene transistors

towards RF (Radio Frequency) applications and also the research on graphene barristor or tunneling transistor towards logic

applications.

[1] H. Yang, J. Heo, S. Science, 336, 1140-1143 (2012)

[2] L. Britnell, R. V. Gorbachev, R. Jalil, et al., Science, 335, 947-950 (2012)


Invited Speech

Nanocrystalline-InZnO Semiconductor Photo-Transistor for Interactive Display Applications

Sanghun Jeon

Department of Applied Physics, Korea University

Ever evolving advances in Zn-series oxide semiconductor materials and devices continue to fuel leading edge

developments in transparent electronics, thanks to new integration processes, enabling large area processing on rigid and

flexible substrates. Oxide semiconductor offers a host of advantages such as low cost and high scalability, in addition to

seamless heterogeneous integration with a host of other inorganic and organic materials in view of its low thermal budget in

processing which provides integration flexibility. However, the oxide semiconductor has one weakness, namely persistent

photo-conductivity (PPC), which leads to a light-induced threshold voltage instability. Despite that, the light-induced

instability can be put to good use as the basis of a high gain photo image sensor, with higher sensitivity than the amorphous

silicon equivalent. In this talk, I am going to present the talk regarding a photo-transistor embedded in a display pixel, in

which gate operation is used to accelerate recovery from PPC. Also, in this talk, the origin of photoconductive gain in oxide

semiconductor will be discussed.


020 ENGE 2013

Invited Speech

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Invited Speech

Materials and Process Aspect of Cross-point ReRAM

Hyunsang Hwang

Pohang Univ. of Science & Technology (POSTECH)

To compete with NAND FLASH technology, we need to develop stackable, cross-point ReRAM device. Although various

materials have been reported, it is difficult to meet device criteria such as high speed operation, low power switching,

switching uniformity, endurance, long-term retention and selection device for cross-point array. We have investigated

various ReRAM devices such as interface switching type (reactive metal/perovskite oxides), filament type (various single

layer binary oxides, and bilayer oxides) and PMC type (Cu-doped carbon, Ag-doped oxide). We found that the scaling of

device area and film thickness improve device performance. Understanding of switching mechanisms and atomic scale film

control are necessary to meet the various requirements for future high density nonvolatile memory devices.

To integrate cross-point (4F2) ReRAM device array, we need to develop bi-directional selector device to suppress the sneak

current path through the unselected devices. Although various selector candidates were recently reported, several problems

such as insufficient current density at set/reset operations for nano-scale devices, low selectivity, and poor endurance

have been raised. In this talk, I will report two types of selection devices, called the varistor-type bidirectional switch (VBS)

and NbOx based threshold switching device with excellent thermal stability. A highly non-linear VBS showed superior

performances including high current density (>3x107A/) and high selectivity (~104). Ultrathin NbO2 exhibits excellent TS

characteristics such as high temperature stability (~160), good switching uniformity, and extreme scalability.



Invited Speech

Functionalized Graphene Flakes for Electronic Application

Seong-In Kim1, S. Y. Choi1, M. S. Shin1, K. H. Lee1, J. H. Kim2, J. W. Chung2

1Cheorwon Plasma Research Institute2Nanocast Tech Co.

Graphene flakes, more specifically nano thickness graphite flakes, have been considered for a various electronic

applications. However, a very few of them has demonstrated a limited success. One of the key issues is a difficult dispersion

of the graphene flakes with the matrix materials. Since the graphene flakes has a 2 dimensional structure, it is imperative

for the surface of the graphene flakes to be reactive. Thus, the functionalization of the garphene flakes should be done at

the surface not just on the edges. In this work, we have used a high temperature RF thermal plasma to modify the graphene

flakes in following three different ways; (1) purification & healing, (2) doping, and (3) metal hybrid.

Graphene flakes are made from liquid acid process and it contains some impurities such as most commonly sulfur and

oxygen. Thermal plasma treatment has shown that oxygen content is reduced down to 1.0% from 9.4% and sulfur is down to

0.8% from 1.5%. Electrical conductivity has also shown to be significantly improved and the surface resistance, 2,200 /sq

of a pressure formed commercially available graphene flakes at 3 m thickness is reduced to 225 /sq at a same thickness.

In order to improve dispersion property and a conductivity of the graphene flakes, N doping has been conducted with a

diaminomethanal using a thermal plasma process and a nitrogen doping content of 4.05 wt% has been achieved. In order to

make the graphene surface active, we successfully make a dispersed nano metal such as Si, Ni, Sn, and Ag, bonding on the

surface of graphene flakes. XRD indicates Si and Ni formed a carbide at the interface.

Sn-graphene hybrid flakes has been used for a heat spreading sheet and a planar thermal conductivity of 660 W/mK has

been achieved, which is considered due to an improved connectivity among graphene flakes by Sn. EMI shielding property is

also significantly improved and has shown less than 20 dB over 0 - 5 Ghz region.

Seong In Kim ()

Cheorwon Plasma Research Institute ()


022 ENGE 2013

Invited Speech

3D Nanostructured, Stretchable Electrodes Made from Proximity Field nanoPatterning

Junyong Park, Changui Ahn, Jerome K. Hyun, Seokwoo Jeon

Graphene Resarech Center, KINC, KAIST

Dep. of Materials Science and Engineering, KAIST

The realization of high stretchability beyond intrinsic limits of electronic materials is important not only from the standpoint

of material science but also from the practical application for flexible electronics. Several strategies have been proposed to

overcome the stretching limits by applying pre-strain or adding two-dimensional (2D) perforating networks. However, huge

potential to extend stretchability by employing nano-structural modifications still remains. Here we report the large area

patterning of three-dimensional (3D) nano-architectures by extending the capability of Proximity field nanoPatterning. State

of the art patterning tools allows to generate 5 by 5 inch area of uniform phase mask that allows extremely large area 3D

patterning capability and new resists increases the penetration depth of electromagnetic waves into recording media (i.e.

resists) above 100 . The 3D nano-structure serve as a sacrificial template for the realization of highly stretchable materials

by infiltrating various materials, especially poly(dimethylsiloxane) (PDMS) in this work. The 3D networked PDMS enables

62% enhancement of stretchability compared to the constituent solid film made of. The 3D structural PDMS has stretched

up to ~225% at optimized elastic modulus and thickness. A stretchable conductor, which contain liquid metal inside the

porous network of the 3D PDMS, show extremely high electrical conductivity of 35,600 S cm-1 at 220% strain with god cyclic

properties. Further applications of 3D nanostructures for optical components will be discussed.

Seokwoo Jeon

Dep. of Materials Science and Engineering, KAIST


Invited Speech

Improved Performance of InGaN/GaN MQW Light-Emitting Diodes by Surface Plasmon

Chu-Young Cho1, Min-Ki Kwon2, Sang-Hyun Hong3, Hyo-Joo Lee3, Seong-Ju Park3

1Department of Electrical Engineering and Computer Science, Northwestern University2Department of Photonic Engineering, Chosun University

3School of Materials Science and Engineering, Gwangju Institute of Science and Technology

In recent years, there has been a remarkably rapid progress in the development of high efficiency InGaN/GaNmultiple

quantum wells (MQW) light-emitting diodes (LEDs). Among many recent approaches to the improvement of internal quantum

efficiency, the increase of radiative recombination by coupling quantum well (QW) to surface plasmon (SP) has been actively

studied for the fabrication of high efficiency LEDs. The overlap of local electric field of SP of metal nanoparticles(NPs) with

the exciton in QW results in an effective resonance between exciton in QW and SP, creating an alternative emission channel.

However, the distance between QW and metal NPs should be in a range of 20 nm for the efficient SP coupling effect. We

have investigated the SP-enhanced LEDs using metal NPs which were inserted into either n-GaN or p-GaN layers in LEDs.

We have successfully demonstrated the SP-enhanced blue, green, NUV LEDs using Ag, Au, and Pt NPs embedded in GaN

layer. The photoluminescence (PL) decay time of LEDs with metal NPs was also faster due to an increase in the spontaneous

emission rate by SP-coupling, resulting in the high optical power of LEDs. It was also found that the SP coupling with exciton

in MQWs can alleviate the efficiency droop of LEDs at high current density. In addition, the transmittance of indium tin oxide

(ITO) layer was increased by Ag NPs and this was attributed to the scattering of light with surface plasmon at the ITO-Ag

interface. In this presentation, the electrical and optical properties of SP-enhanced LEDs will be addressed.

Seong-Ju Park

School of Materials Science and Engineering, Gwangju Institute of Science and Technology



Invited Speech

Large-area Nano-Electronics and Lithography using Nanowire Printing

Sung-Yong Min1, Tae-Sik Kim1, Beom Joon Kim2, Himchan Cho1, Yong-Young Noh3,

Hoichang Yang4, Jeong Ho Cho2, Tae-Woo Lee1

1Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH)2SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University

3Department of Energy and Materials Engineering, Dongguk University4Department of Advanced Fiber Engineering, Inha University

Although the many advantages of nanowires (NWs), a reliable process for large-scale and controllable assembly of

aligned NW arrays based on individual control (IC) of NWs is necessary because inorganic NWs are mostly grown vertically

on substrates and thus have been transferred to the target substrates by any of several non-individually controlled (non-

IC) methods such as the random dispersion method with disordered alignment, and contact-printing technologies with

unidirectional massive alignment. Controlled alignment and patterning of individual semiconducting nanowires at a desired

position in a large area is a key requirement for practical electronic device applications. High-speed, large-area printing of

highly-aligned individual nanowires that allows control of the exact numbers of wires, and their orientations, and dimensions

and its use in high-speed large-area nanolithography is a significant challenge for practical applications. Here we use

a high-speed electrohydrodynamic organic nanowire printer to print large-area organic semiconducting nanowire arrays

directly on device substrates in a precisely individually-controlled manner; this method also enables sophisticated large-

area nanowire lithography for nano-electronics. We achieve an unprecedented high maximum field-effect mobility up to

9.7 V-1s-1 with extremely low contact resistance (

024 ENGE 2013

Invited Speech

Stability of Electrical Doping in Organic Semiconductors

Jae-Hyun Lee1, Chur-Hyun Shin2, Eul Yong Shin2, Yoonseuk Choi2

1School of Global Convergence Studies, Hanbat National University2Department of Electronics, Hanbat National University

Electrical doping in organic semiconductors is an important technique to reduce the driving voltage and improve the power

efficiency of organic electronic devices. Electrical doping in charge transporting material can reduce the contact resistance

between electrodes and organic materials and can enhance the electrical conductivity of charge transporting layer. Based

on these recent results, highly efficient organic light emitting diodes (OLED), organic photovoltaic cells (OPV) and tandem

structured organic devices have been realized using p-doped/intrinsic/n-doped (p-i-n) structures. However, the nanocluster

formation of p-type dopants (molybdenum oxide and rhenium oxide) by the aggregation of dopant molecules and the

diffusion problems of n-type dopant such as alkali metal (lithium and cesium) have been referred as the reason of instability

of doped organic semiconductor layers. In this presentation, we will demonstrate the stability characteristics of electrical

dopants and their effect to the device performance by the analysis of doped/undoped organic interface and organic p-n

junction with the impedance spectroscopy.


Invited Speech

Manipulation of Light for Autostereoscopic 3D Displays

Hyunsik Yoon

Department of Chemical & Biomolecular Engineering, Seoul National University of Science & Technology

Since the movie Avatar came out in 2009, three dimensional displays have been received much attention in industries.

Especially, autostereoscopic 3D displays, which imply one can perceive 3D images without wearing special glasses, is known

as the technology to be developed for the convenience of users. After introducing the principle of autostereoscopic 3D displa

ys, in this talk, historical methods to manipulate light such as the parallax barriers and lenticular lens arrays as well as the

recent progress on the technologies such as 2D/3D conversion will be presented. Then, the recent work on the directional

optical components of the Lucius prism array will be highlighted as an optical component for autostereoscopic 3D displays or

dual view displays.

Hyunsik Yoon ()

Seoul National University of Science & Technology ()



Invited Speech

Ab-Initio DFT Discovery of High Functional Catalysts for Fuel Cell Application

Seunghyo Noh, Junkyo Seo, Dohyun Kwak, Minho Seo, Byungchan Han

Department of Energy Systems Engineering, DGIST

Environmental degradation caused by harvesting fossil fuel-based energies has strongly driven to develop next generation

of renewable power sources. Fuel cell technology is one of the most attractive options. High materials cost, low activity

towards oxygen reduction reaction (ORR) and weak durability of Pt-based catalysts, however, are currently the major

challenges of fuel cells to a wide commercialization of the technology.

Discovery and development of top-grade energy materials essentially require accurate but fast methodologies enabling

us to describe and understand underlying mechanisms of complicated chemical reactions. In this talk, first principles as

well as multi-scale computations are extensively utilized to design novel fuel cell catalysts by sorting out target materials

from gigantic amounts of candidates. It is shown that rigorous electronic structure calculations with thermodynamic and

electrochemical interpretations are the major tools in such a successful outcome.

Byungchan Han

Department of Energy Systems Engineering, DGIST


Invited Speech

High Mobility Thin Film Transistors based on Zinc Oxynitride Semiconductors

Joon Seok Park, Hyun-Suk Kim, Tae Sang Kim, Eok Su Kim, Kyoung Seok Son, Jong-Baek Seon, Sunhee Lee,

Seok-Jun Seok, Sun-Jae Kim, Myungkwan Ryu, Seong-Ho Cho, Youngsoo Park

Compound Device Lab, SAIT, Samsung Electronics, Inc.

Recent needs for high performance devices in the flat panel display industry have triggered the search for high mobility

semiconductors. In the past few decades, the fabrication of active matrix liquid crystal display (AMLCD) panels has involved

the integration of thin film transistors (TFTs) based on amorphous silicon (a-Si). Although the latter is still the semiconductor

of choice in the current AMLCD market, its relatively low electron mobility (< 1 /Vs) imposes limits on the maximum display

size that can be achieved without compromising the image resolution and/or operating frequency.

In this work, high mobility TFT devices that incorporate zinc oxynitride (ZnON) semiconductors are presented. ZnON films can

be deposited onto glass substrates by reactive magnetron sputtering using a zinc metal target. It is found that the most critical

parameter affecting the electrical properties is the ratio of nitrogen to oxygen gas flow rates during ZnON growth. Regardless

of the final composition, all ZnON films are n-type, and the electron mobility increases as the layers become rich in nitrogen.

Microstructural analyses indicate the nitrogen-rich films consist of zinc nitride (Zn3N2) nanocrystals embedded in an amorphous

Zn-O-N matrix, while additional oxygen induces a mixture of nanocrystalline Zn3N2 and zinc oxide (ZnO) phases.

The high mobility compositions of ZnON allow the fabrication of TFT devices with field effect mobility values exceeding 100

/Vs, however for practical use the off current levels and subthreshold swing need to be reduced. In that regard, the addition

of cations such as gallium (Ga) is found to be effective, since the dopant acts as a carrier suppressor in the host material.

Hence, realistic devices with field effect mobility near 50 /Vs are routinely obtained.

Joon Seok Park

SAIT, Samsung Electronics, Inc.

E-mail [email protected], [email protected]

026 ENGE 2013

Invited Speech

Role of Buffer Phase in the Si-based Anode Materials for Li-ion Battery

1, 2, 2, 1

1Department of Energy Engineering, Hanyang University2Advanced Batteries Research Center, Korea Electronics Technology Institute

Silicon has gained much attention as an alternative anode material for replacing graphite anode material due to its high

energy density. However, a major drawback of this material is poor cycle performance caused by a large volume change

associated with alloying/dealloying reaction with lithium. Volume expansion and followed contraction of Si during cycling lead

to degradation of the electrode material and breakdown of the electrical conduction pathways within the electrode, thereby

causing capacity fading. In order to solve this problem, numerous material concepts have been suggested and some of them

proved to be effective in improving the capacity retention characteristics. One of the effective ways to enhance the cycle

performance of silicon is the use of active/inactive composite material where inactive phase represents either inactive phase

to lithium or less active phase than Si such as carbonaceous materials. Inactive phase is likely to serve both as a matrix where

Si is finely dispersed and as a buffer to relieve the influence of Si expansion and to preserve the structural integrity of the

electrode material during cycling. Among these, Si/carbon composites have attracted considerable attention since carbon is

good electrical conductor and shows a negligible volume change during cycling. Buffering phase, such as nanopore, polymer

matrix and less active carbons, can play a key role of improving the electrochemical performances of Si based anode materials

against huge volume change of silicon during cycling, suggesting that this phase might be e effective in absorbing and releasing

the mechanical stresses/strains caused by alloying/dealloying reaction of Si and thereby to reduce the volume change of the

electrode material, compared to other inorganic inactive materials. In this presentation, buffering phase embedded Si based

anode materials will be discussed to assess its potential use as an anode material for lithium rechargeable battery.


Invited Speech

Thermally Driven Solid Solution Nano-sized LixFePO4and their Chemical Properties

Byoungwoo Kang

Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH)

LiFePO4 is the most promising cathode material, especially for electric vehicle (EV) because of its inexpensive cost, its

superior thermal and structural safety, and its non-toxicity. Although LiFePO4 has been believed to be poor conductor due to

its low electronic conductivity and 1D lithium diffusion, nano-sized LiFePO4 shows the fastest electrochemical reaction during

charging/discharging.

To understand this intriguing behavior, phase transformation behavior during charging/discharging should be considered.

Recently, several calculations1,2 suggest that typical two-phase reaction can be depressed in nano-sized LiFePO4 material.

In this study, we will explore phase transformation behaviors of LiFePO4 based on experiments. For this purpose, we will

utilize thermally activated LixFePO4 which can be in solid solution in certain conditions.3

We synthesize nano-sized or micro-sized LiFePO4 materials by simple solid state reaction. And then, LixFePO4 materials

with different values of x are prepared by chemical oxidation with NO2BF4 in acetonitrile. In this talk, we will discuss about the

phase transformation behaviors of thermally driven solid solution LixFePO4 and their chemical properties and try to translate our

findings to electrochemical reaction of LiFePO4 in the cell.

Byoungwoo Kang

Department of Materials Science and Engineering, Pohang University of Science and Technology



Invited Speech

Important Physical Factors Determining the Activity of Catalysts for Li-O2 Battery Applications

Yong-Mook Kang

Department of Energy & Materials Engineering, Dongguk University-Seoul

The energy density of the conventional lithium ion battery cannot meet the stringent requirements for electric vehicle

(EV) and large-scale energy storage system(ESS), whereas lithium-air batteries have significantly high theoretical specific

energy coming up to 11,140 Wh/kg because lithiumair batteries are based on discharge reaction between Li and oxygen

to yield Li2O2. However, regardless of its high energy density, low cycling capability remained as an important hurdle for

commercialization. A major drawback about lithium-air batteries is its low round trip efficiency coming from very large

potential difference between ORR and OER (Oxygen evolution reaction). Various types of materials have been adopted for

the catalysts to reduce potential hysteresis and thus attain high round-trip efficiency. -MnO2 has received great attention as

an oxide catalyst for lithium-air batteries since its superior catalytic activity was introduced by P. G. Bruce et al.. However,

couple of previous piecemeal approaches without detailed understanding on the fundamental physical properties governing

the catalytic activity of materials failed to make a breakthrough in the development of commercially available catalysts.

Hence, we here report on the [200]-oriented -MnO2 nanowires or surface-arranged -MnO2 nanowires having

thermodynamically metastable surface with significant instability and more open-structured surface frame ascribed to its

cross-sectionally orderded 2x2 channel resultantly enabling more homogeneous nucleation of Li2O2 without toroidal growth

and more effective Li2O2 accommodation compared to the [002]-oriented -MnO2 nanowires. The dependence of catalytic

activity on the growth direction and other surface arrangement has been predicted based on the state-of-the-art first

principles calculation on low miller index planes as main sidewall surface planes. To experimentally confirm the calculation

results, very facile route based on hydrothermal reaction will be also introduced to abnormally grow -MnO2 nanowires along

[200] direction or with other surface arrangement. Finally, some physical parameteres related to alloy catalysts will be also

explained in this presentation.

Yong-Mook Kang

Department of Energy & Materials Engineering, Dongguk University-Seoul


028 ENGE 2013

Invited Speech

Development of NASICON Li3V2(PO4)3 Material for Lithium Battery

LiCoO2

Co , Co

. LiCoO2 LiMn2O4

.

, Ni LiNi0.5Mn1.5O4 5V . LiNi0.5Mn1.5O4 Mn 16d

Ni LiMn2O4 LiMn2O4 Ni2+ Mn2+ ,

LiMn2O4 4.04.2V 4.54.8V .

LiNi0.5Mn1.5O4 NiO ,

LiNi0.5Mn1.5O4 Ni2+ Mn3+ Mn3+ .

. , Mn3+ Jahn-teller distortion

. Mn

,

.

- LiNi0.5Mn1.5O4 . ,

LiNi0.5Mn1.5O4 ,

Mn

LiNi0.5Mn1.5O4 ,

.



Invited Speech

(UNIST)

To meet the high demands for energy storage systems including smart grid and electric vehicle applications, the

development of next generation rechargeable batteries is urgently required. Among the various post rechargeable battery

systems, sodium ion batteries are considered one of the promising candidates due to the natural abundance and low toxicity

of Na resources, and good electrochemical performance. However, there have been still limited studies on sodium insertion

materials.

This presentation will discuss new promising electrode materials for Na ion batteries.1) First of all, a new polyanion-based

compound, Na3.12M2.44(P2O7)2 (M=Fe, Fe0.5Mn0.5, Mn, Co) is introduced as a cathode for Na ion batteries. Off-stoichiometric

synthesis induces the formation of a Na-rich phase, Na3.32Fe2.34(P2O7)2 as a solid solution phase, and this delivers a reversible

capacity of about 85 mA h g-1 at ca.3 V vs. Na/Na+ with very stable cycle performance. Also, it shows fast kinetics for Na

ions due to the spacious channel size along the a-axis.2) Disodium terephthalate and its various derivatives as an anode

are also presented. Disodium terephthalate shows excellent electrochemical performance including nigligible capacity fading

over 90 cycles, ideal redox potential (0.4 V vs Na/Na+), and excellent rate performance. In addition, its redox potential can be

controlled via the addition of functional groups due to inductive effect.3) Finally, we introduce an amorphous red phosphorus/

carbon composite obtained through a facile and simple ball milling process. The composite shows promising electrochemical

performance including high specific capacity of 1890 mA h g-1, negligible capacity fading over 30 cycles, ideal redox potential

(0.4 V vs Na/Na+), and good rate performance.



[ENGE-038] Devices and Materials for Energy Harvesting and Storage

Influence of CNT Incorporation on the Photovoltaic Behavior of TiO2 Films formed by High-voltage Electrophoretic Deposition

Eung Seok Lee, Kang Min Lee, Ki Ryong Shin, Bongyoung Yoo, Dong Hyuk Shin

Hanyang University

This study examined the effects of incorporated-carbon nanotubes (CNTs) on the photovoltaic response of a mesoporous

TiO2 film on a titanium foil subjected to electrophoretic deposition (EPD) at a high voltage of 350 V for use in dye-sensitized

solar cells (DSSCs). Microstructural observations showed that after EPD in an alkaline electrolyte for 40s, the surface area

of the CNT/TiO2 film was relatively higher than that of its TiO2 counterpart. This was attributed to the incorporated CNTs

triggered, local agglomeration of TiO2 nanoparticles during EPD. The DSSCs with the CNT/TiO2 film exhibited a higher short-

circuit current density than the cell with the TiO2 film, whereas the open circuit voltage remained constant for both cases.

The power conversion efficiency of the CNT/TiO2 film approached 2.49% due to the increased surface area of the film, which

facilitates increased dye absorption. Electrochemical impedance analysis showed that the charge transport resistance at

the interface between the photoelectrode and electrolyte decreased when the CNTs were incorporated. This was attributed

mainly to the incorporation of CNTs, which provide interpenetration paths for electrons across the entire photoelectrode.


1, 2, 1

1 /2

. , TiO2

. TiO2 , , , , ,

. TiO2 anodization .

TiO2 . XPS .

state . 2

. . 1

Ti-O-C XPS .

. 3.32eV 1.7eV .

400~700nm TNTAs 350% . UVVis spectra

. ,

TiO2 .

034 ENGE 2013


Photocatalytic Properties of Cu2Te NPs/TiO2 Nanotubes for Hydrogen Production

,

.

4% 43%

. TiO2 .

. (3.2eV)

(2.2eV) p Cu2Te

. , , pn

. ,

, , Potensiostat(Cyclic Voltammetry) , ,

.


p-type CuO Electrodes for Solar Hydrogen Production by Splitting Water inSelf-bias Photocatalytic Systems

,

.

4% 43%

. n

TiO2 p CuO , , /

. TiO2 FTO

CdS(2.4eV), CdSe(1.7eV)

. CuO FTO

2 . 1 CuO

. (1.2eV) / .

ZnO/TiO2 .

, , Potensiostat(Cyclic Voltammetry) ,

0V

~1.5mA/ .



High-Performance of P-type Polymer Hybridized ZnO Thin Film Piezoelectric Nanogenerator

, ,

Enhancing the output power of a nanogenerator is essential in applications as a sustainable power source for wireless

sensors and microelectronics. We report here a novel approach that greatly enhances piezoelectric power generation by

introducing a p-type polymer layer on a piezoelectric semiconducting thin film. Holes at the film surface greatly reduce the

piezoelectric potential screening effect caused by free electrons in a piezoelectric semiconducting material. Furthermore,

additional carriers from a conducting polymer and a shift in the Fermi level help in increasing the power output. Poly(3-

hexylthiophene) (P3HT) was used as a p-type polymer on piezoelectric semiconducting zinc oxide (ZnO) thin film, and

phenyl-C61-butyric acid methyl ester (PCBM) was added to P3HT to improve carrier transport. The ZnO/P3HT:PCBM-

assembled piezoelectric power generator demonstrated 18-fold enhancement in the output voltage and tripled the current,

relative to a power generator with ZnO only at a strain of 0.068%. The overall output power density exceeded 0.88 W/cm3,

and the average power conversion efficiency was up to 18%. This high power generation enabled red, green, and blue light-

emitting diodes to turn on after only tens of times bending the generator. This approach offers a breakthrough in realizing a

high-performance flexible piezoelectric energy harvester for self-powered electronics


-

1, Haq Ul Atta1, 2

12

.

,

. -

. ,

. -

- .

, .

036 ENGE 2013

[ENGE-019] Lithium and Advanced Battery Materials

Microstructural and Electrochemical Properties of LiCoO2 Thin Film Prepared by Aluminum Induced Crystallization (AIC) Method

1, 1, 1, 2, 1, 1

1 2

The thin film micro-battery has potential applications in microelectronics such as backup power for on-chip static

memory modules, micro power sources for metal-oxide-semiconductor [1]. LiCoO2 is presently the most widely used

cathode in rechargeable Li-ion batteries due to its high capacity and good cyclability [2]. LiCoO2 has good electrochemical

properties at the complete crystallization. but as-deposited LiCoO2 thin films have amorphous. Therefore the heat

treatments for crystallization of as-deposited films are necessary. It is reported that the crystallization of LiCoO2 started

from 400C, and complete crystallization occurred over 600C [3]. Recently, many studies for lowering the crystallization

temperature of LiCoO2 thin film have been carried out.

In this work, we used Aluminum Induced Crystallization (AIC) method for lowering the crystallization temperature. The

micro-structural and electrochemical properties of LiCoO2 thin film fabricated by AIC method were investigated.

References

1. J. B. Bates, N. J. Dudney, B. Neudecker, A. Ueda, C. D. Evans, Solid State Ionics, 135 33 (2000)

2. P. Birke, W. F. Chu, W. Weppner, Solid State Ionics, 93 1 (1997)

3. R. Kohler*, P. Smyrek, S. Ulrich, M. Bruns, V. Trouillet, W. Pfleging, Journal of fo optoelectronics and advanced

materials, 12 3 (2010)


,

, ,

. ,

, .

, .

poly(vinylidene fluoride trifluoroethylene) [P(VDF-TrFE)]

. P(VDF-TrFE) ,

30 .

, .



SI-C

, , ,

, .

.

, battery

.

.

SI base ,

. FE-SEM XRD . , TOSCAT 3000

/ (1.0~3.0V) , (10 mA/g) test .

.


Electrochemical Properties of Metal Doped LiFePO4 Cathode Material for Lithium Ion Batteries

1, 1, 1, 2, 1

1 2

Olivine-type LiFeO4 has a high environmental acceptability, long cycleability and low cost, and it is therefore the most

promising cathode material for largescale rechargeable batteries used for hybrid electric vehicles (HEV). Especially, theoretical

density calculated by the lattice constant and molecular weight was 3.6 g cm-3. Although it is a bit small compared with

LiCoO2 (5.1 g cm-3), LiNiO2 (4.8 g cm-3) and LiMn2O4 (4.2 g cm-3), but larger than other phosphates. However, LiFePO4 cathode

materials have the disadvantage of poor electronic conductivity. Its poor rate capability has been attributed to low electronic

conductivity (10-9 S cm-1) and slow diffusion of lithium ions across the two-phase boundary. In order to improve these

shortcomings of LiFePO4, decreasing particle size, carbon coating, cation exchange and other methods have been used.

In this study, LiFePO4 cathode material was prepared by one-step sintering method at 600 and to improve electronic

conductivity, the Ti and Mg-doped LiFePO4 were prepared and their electrochemical performance was studied. Prepared

cathode materials do not show the appearance of impurity phase. Prepared LiFePO4 exhibits a discharge capacity of 129 mAh

g-1 at the first cycle and 135 mAh g-1 after 30 cycles. Phosphor-olivine Ti-doped LiFePO4 possesses 3.36 V flat voltages on

discharge curve and shows a gentle decline compared to undoped LiFePO4 without great changes of capacity, and displays

the improved discharge capacity of 139 mAh g-1. The method of using transition metal replacement was used to improve

charging/discharging characteristics and low electronic conductivity of LiFePO4. The electrochemical properties of LiMxFe1-

xPO4 (M=Ti, Mg, and x=0, 0.05, 0.1) were analyzed by charging/discharging and ac impedance tests.

038 ENGE 2013


Pre-doping Li-ion

, , , , , ,

COSMO

Li-ion , , .

, Li-ion .

, 4.5V ,

(/) . Al, Zr, Mg, Ti ,

, .


Thermal Stability and Electrochemical Properties of High Capacity LiMnBO3 Synthesized by Simple Synthesis Method

1, 1, 2, 1

12

During the past decade, lithium ion batteries have been investigated and widely used as the main rechargeable power

sources and the needs of lithium-ion batteries have been expanding toward large-scale application such as hybrid electric

vehicles (HEV) and plug-in hybrid electric vehicle (PHEV) due to its high operation voltage, high gravimetric energy density

and long cycle life. Olivine-type lithium iron phosphate was introduced by Goodenoughs group in 1997. Since LiFePO4 was

proposed, it has attracted considerable attention as a cathode material in lithium ion batteries for electrical storage device for

HEV and PHEV due to its low toxicity and high stability. [1] However, the high energy density for the large scale application

still have not solved yet with 170 mAh/g of LiFePO4. In this regard, alternative polyanionic structures which consist of borates

have become attractive as they exhibit a high theoretical capacity of 220 mAh/g with a better electrical conductivity and a

similar volume energy density compared to LiFePO4.

In this work, we propose a simple synthesis method to improve the electrochemical properties of lithium manganese borates.

The specific capacities of the lithium manganese borate could be increased by using different lithium content ratio in the

precursor. Carbon coated Li1.0MnBO3 and Li1.5MnBO3 are prepared and their thermal stability and electrochemical properties

are investigated by using time-resolved X-ray and galvanostatic charging/discharging. The specific charge/discharge

capacities of lithium manganese borate are improved with increasing the lithium content. The discharge capacities of

Li1.0MnBO3 and Li1.5MnBO3 was 67 mAh/g and 150 mAh/g within 1.5~4.5V at C/20 rate. Time resolved X-ray diffraction data

verifies that the lithium manganese borate composed of polyanion is very stable during heating up to 600C


[ENGE-014] Photovoltaic Science

Cu(In,Ga)Se2 (CIGS)

1, 2, 1

1 /2

CIGS 2um . CIGS

, 20% Si

.

CIGS /P-type CIGS//N-type intrinsic ZnO/Al-doped ZnO /

. CIGS/ , . Carrier

, . , Valence band offset

Conduction band offset Band alignment CIGS CIGS/ design

. CIGS Ordered vacancy compound (OVC) In-rich CuIn3Se5 . Vacancy

Cu acceptor , Se donor OVC . CIGS

surface chemistry .

CIGS (1) (In-final, Ga-final)

(2) X-ray Photoelectron spectroscopy Zn(O,S) buffer S% Conduction band offset

. OVC near surface Cu . Sputtering Cu2p peak Chemical

transition high binding (Top-surface Cu poor Near-surface Cu rich ) . Ga

. Cathodoluminescent .

Zn(O,S) S 14% (33, 50, 80%) , CBO 1eV ,

. S 14% , CBO 0.5eV 14.6% . , CBO CIGS

.


, ,

,

. , (effective optical thickness)

. TiO2

. ,

.

040 ENGE 2013


One-Pot Synthesis of Peacock-Shaped TiO2 Light Scattering Layer with TiO2 Nanorods Film for Dye-Sensitized Solar Cells

Nowadays, the exploration of new photoelectrode architectures to improve the light-harvesting and charge-collection

properties of sensitized solar cells and related devices has been regarded as a challenging work. Here, we demonstrate

one-pot synthesis of peacock-shaped TiO2 light scattering layer with TiO2 nanorods film for dye-sensitized solar cells by

hydrothermal method controlling the acid ratio of HCl and CH3COOH. In the case of 1:2 ratio of HCl:CH3COOH, the one-

dimensional (1-D) TiO2 nanorods (NRs) film was synthesized with a length of 2 m, whereas 1-D TiO2 NRs film with peakcock

shaped TiO2 nanobundles as a light scattering layer (LSL) was acquired in the 2:1 ratio of HCl:CH3COOH. This LSL showed

the remarkably dual functions in an aspect of high light harvesting attributable to the large surface area due to micrometer-

sized TiO2 nanobundles consisting of small-sized TiO2 NRs with approximately 30~40 nm sized diameter and light scattering

effect in the long wavelength of 550-700 nm. Accordingly, this dual functions of LSL result in the sharp increased conversion

efficiency (3.93%) about above two times compared to that (1.49%) of TiO2 NRs film synthesized in 1:2 rato of HCl:CH3COOH.


Cu2O

, , ,

(Cu2O) 2.1eV ,

, 19% . CIGS

Cu2O

. Cu2O , ,

, Cu2O

.

ITO/glass Cu2O p-Cu2O/n-ZnO

Cu2O/ZnO . Cu2O

pH Cu2O , I-V . pH 11

Cu2O (111) , pH OH-

. ZnO AZO

1200nm , ZnO 100 300nm

pH 11 Cu2O . Cu2O (pH 11)/ZnO

0.27% (0.13%)

.



1, 1, 1, 2, 2

12

.

11% .

, , .

.

Red shift .


Bifunctional TiCl4 Treatment in CdSe Quantum Dots Sensitized TiO2 Microrods for Photoelectrochemical Water Splitting

Since Fujishima and Honda first adapted titanium dioxide (TiO2) semiconductor as a photoanode for a solar light-driven

water splitting cell, considerable attention has been focused on enhancing the photoelectrochemical (PEC) conversion

efficiency [1]. Generally, TiO2 has been regarded as one of the most promising materials due to its excellent photocatalytic

activity, low cost, and chemical stability [2]. However, the energy band-gap of TiO2 is too large to allow for efficient visible-

light absorption. Thus, advancing the visible light harvesting ability of TiO2 has been considered a key issue. One of

challenging works, the sensitization of TiO2 with quantum dots (QDs) was performed with the TiCl4 treatment showing the

bifunctional effects. At first, TiO2 microrods (TOMRs) were synthesized using a facile hydrothermal method and subsequently

surface-treated with TiCl4 solution at different concentrations. CdSe QDs were assembled on the TiO2 films as a sensitizer

to improve the light harvesting efficiency in visible light, because the TiO2 absorbs only UV light. As the concentration of

TiCl4 solution to 200 mM was increased, the surface coverage of anatase TiO2 nanoparticles and the loading of CdSe QDs

also increased. Furthermore, the anatase TiO2 between the rutile TOMR and the CdSe QD facilitates the charge separation,

which suppresses the charge recombination. Due to these beneficial effects, the photoelectrochemical performance was

significantly enhanced with the increased TiCl4 concentration.

References

[1] Fujishima A, Honda K. Nature 1972; 238: 37-39.

[2] Kang S H, Lim J -W, Kim H S, Kim J -Y, Sung Y -E. Chem. Mater 2009; 21: 2777-2788.

042 ENGE 2013


H2S Cu2ZnSnS4

1, 2

1 (SAINT)2

Cu2ZnSnS4 >104 cm-1 ~1.5 eV

. Cu2ZnSnS4

. slufurization

. Raman spectroscopy, XRD(X-ray diffraction)

, SEM(Scanning Electron Microscopy)

. XRF(X-Ray Fluorescence) AES(Auger Electron Spectroscopy)

.


ZnO

1, 2, 1, 1, 2, 1

12

ZnO ,

ZnO . ZnO

AFM ZnO morphology , ITO ZnO films

Jsc (short-current density) FF(Fill factor) .

, Chlorobenzene(CBZ) 2-Propanol (IPA) 5 : 5 open circuit

voltag (Voc) 0.61 V, FF 60%, Jsc 10.05 mA/ , 3.74%

.



Cu2ZnSnS4

, Arun Khalkar, ,

Cu2ZnSnS4 CIGS , 8% .

Se , Cu2ZnSn(S,Se)4 10% IBM . CZTS CIGS

, Zn,Sn CZTS

. CZTS co-evaporation, sputtering, electro-deposition, solution

. CZTSSe , CZTS

CIGS . sputtering

sulfurization CZTS , Cu, SnS, ZnS co-sputtering , 550

sulfurization CZTS . CZTS , Cu-rich

Cu2S , window layer p-n shunting path ,

. CZTS 10wt% KCN ,

CZTS . optical microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy(XPS)

CZTS .


Combinatorial Magnatron Sputtering Flexible CuGaSe2

1, 1, 2, 1

1 2

90% Si() ,

, CIS 10-5cm-1 1~2m

[1]. Cu, In, Ga, Se Co-evaporation

Se Sputter

, Sputter Cu/In/Ga DC H2Se/H2S

.

, CGS CGS

. , glass ,

.

CGS stoichiometric compound single target combinatorial magnetron sputtering system

, 25~200 . (PI) 0.2~1.5m CGS

, XRD , CGS chalcopyrite peak ,

2 phase . CGS

. , chalcopyrite peak . Raman

spectroscope chalcopyrite .

, 100~200 , 1.5~1.6eV , CGS

, chemical composition .

sputtering target CGS ,

.

044 ENGE 2013


ALD Zn(O,S)

1, 1, 1, 2, 2

1() 2()

CIGS , Cd-free (Buffer

layer) Zn(O,S) . Zn(O,S) Sputtering, MOCVD(Metal-

organic chemical vapor deposition), ALD(Atomic layer deposition) .

ALD(Atomic layer deposition) (Precursor) DEZ(Diethylzinc) H2O H2S (50~150 cycle)

Zn(O,S) . DEZ H2O N2gas , .

XRD(X-ray diffractor), XPS(X-ray photoelectron spectroscopy), AFM(Atomic force microscope), FE-SEM(Field

emission scanning electron microscopy) . Zn(O,S) 31~68 nm ,

(400~700 nm) 90% . XRD

ZnO(100)/(002)/(101) ZnS(111)/(220) , H2O:H2S 6:1 ZnS(220)

. (Ra) 1.02 nm 0.80 nm , H2O:H2S

. XPS Zn(O,S) (B. E) .

Cd-free Zn(O,S) ALD .


CuIn(Se,S)2

1, 2

1 2

CIGS absorption coefficient 1~2um

. , CIGS co-evaporation 20% co-evaporation

. CIGS

Si .

,

,

. three dimension structures PV cell , back contact metal absorber layer interfacial area

electrode recombination .



One-step Sputtering CIGS

1, 2, 1, 1

1 2

, , .

CIGS, CdTe, AsGa . Chalcopyrite

CIGS . CIGS

co-evaporation, sputtering, co-evaporation

.

PI CIGS one-step sputtering 0.1 m 1.3 m CIGS

, 200 CIGS .100

PI CIGS 0.1 m 1.1 m CIGS (112) (204)/

(220) main peak , 0.6 m CIGS (112), (204)/(220) peak . 1.3 m CIGS (116)/(312)

peak . CIGS main peak 1.3 m 150 200 CIGS main peak

CIGS (116)/(312) peak . PI CIGS

. CIGS peak 1.3 m XRD , 100

CIGS main peak CIGS (116)/(312) peak

. 1.3 m CIGS Raman

.


Co-sputtering Deposition and Characterization of Cu2ZnSnS4 Thin Film Absorber Layer for Solar Cells

Arun Khalkar, , ,

Cu2ZnSnS4 (CZTS) thin films were deposited using the co-sputtering technique. The growth parameters, such as working

pressure, target powers and post annealing atmosphere, were optimized for CZTS films deposition. A comparative study

between post annealing using sulfur vapor in a quartz tube furnace and sulfurization chamber using H2S gas was carried out

to optimize the kesterite Cu2ZnSnS4 phase. Annealing in the furnace in sulfur vapor eliminated all the secondary phases and

formed kesterite Cu2ZnSnS4. The diffusion of sulfur in the film during the annealing process enhanced the crystallinity of the

film. The kesterite Cu2ZnSnS4 phase was confirmed by x-ray diffraction, Raman scattering and optical measurements. The

film showed phonon peaks corresponding to the kesterite CZTS, high absorption coefficient (1.1105 cm-1) and desired optical

direct band gap (1.5 eV). The resistivity, carrier concentration and Hall mobility of the film were 79.33Wcm, 1.11016 cm-3 and

7.11 /Vs respectively. The solar cell fabricated with SLG/Mo/CZTS/CdS/i-ZnO/Al:ZnO/Ni/Al. The CZTS absorber layer

used in solar cell was prepared by sulfurization at 550C for 1 hour in S vapor atmosphere.

046 ENGE 2013


Photo Resist Nanoimprint Honeycomb Pattern Texturing

, , ,

Si solar cell texturing .

. .

texturing .

Photo resist resin nanoimprint . Photo resist

. Nanoimprint pattern roll to roll

. Mold mask 1, 3 hole hole 10 honeycomb pattern. Mold

PDMS(sylgard A : sylgard B = 10 : 1) . Resin positive PR spin coating Si

. Pattern Mold photo resist pattern .

HF:HNO3:CH3COOH etching time pattern

etching profile . solar cell

. Solar wafer . solar wafer

solar cell .


One-step Sputering CIS

1, 1, 2, 1

1 2

Chalcopyryte CIS 10-5cm-1 1~2 m

, . ,

. CIS . CIS

Cu, In, Ga, Se co-evaporation .

19.9% , 3-stage . sputtering

CIS

.

. Se ,

, CIS .

Se CuInSe2 (CIS)

. CIS combinatorial sputtering system , Ar

. PI(Polyimide) Se CIS CIS .

CIS XRD (secondary phases) chalcopyrite CIS

, RAMAN CIS . CIS , ,

, .



CdS/CdSe Co-sensitized TiO2 Nanorods for Solar Cells

,

.

, , ,

. (, ), (- -

), ( ), .

, .

. TiO2

(3.2eV) 4% 43%

. TiO2

, . CdS(2.4eV), CdSe(1.7eV)

SILAR . CdSe/CdS/

TiO2 3 . TiO2

(S2-) .

, , , FESEM, TEM, XRD .


High Transparent TiO2/Au Grid poly (3, 4 Ethylenedioxythiophene): p-toluene Sulfonate Hybrid Electrode for ITO Free Organic Solar Cells

Myeonggi Kim1, KiYeul Yang2, Md.Maniruzzaman1, Chiyoung Lee2, Hoseok Nam1, Jaegab Lee2

1School of Advanced Materials Engineering2Kookmin University

Transparent conductive oxides (TCO) are widely used in thin film optoelectronic devices. Indium-tin Oxide (ITO) is the most

important single layer transparent conductor. But there are technical and economic limitations for a large scale manufacturing

of flexible devices. Recently, Metal-conjugated polymer hybrid structure has been actively researched to replace of ITO

because the hybrid structure can produce transparent, low resistance.

In this study, We fabricated a hybrid electrode by developing Au grid and tosylate doped poly(3,4-ethylenedioxythiophene:

p-toluene sulfonate) (PEDOT:PTS) connection path with optimized Au grid aperture ratio. Au grid-PEDOT:PTS was deposited

on the TiO2 which remarkably increased the transmittance. Organic solar cells fabricated on the TiO2/Au grid-PEDOT:PTS

hybrid electrode showed a power conversion efficiency of 3.88%, comparable to that of ITO-based organic solar cell (3.91%).

The TiO2/Au grid-PEDOT:PTS hybrid electrode shown to be promising replacement of ITO for use in low-cost and flexible

optoelectronic devices.

048 ENGE 2013


BBr3 Boron Doping Solar Cell

Wafer CZ n-type (100) , wafer 200. Process 900~1000

. Sheet resistance uniformity N2 gas . gas BBr3 O2 sheet resistance

lifetime . gas 2:1 lifetime . Process sheet resistance

junction depth . Doping 2-step . Drive-in junction

depth O2 . Boron doping wafer BSG(Boron silicate Glass) layer .

HF dipping . BSG(Boron silicate Glass) BRL(Boron Rich Layer)

FE-SEM(Field Emission Scanning Electro Microscope) . Process BRL

. 13nm ~ 17.76nm . PESC solar cell . boron doping

mask layer Phosphorous doping . PSG(Phosphorous Silicate Glass) HF

. PECVD SiO2 passivation . Passivation 120nm~ 160nm . Ni/

Cu plating photolithograpy patterning . Seed layer Ni

. Electroless plating Ni . Ni resistivity annealing

NiSi . LIP(Light induced plating) electro plating Cu

. 15.28% .


, ,

KAIST

.

(0.2-5.0 wt%) P3HT:PCBM PTB7:PCBM ,

. , 1.5 wt% PTB7:PCBM

8.6% .



Efficient ITO-free Organic Solar Cells with Highly Conductive andTransparent MoO3/Au/MoO3-PEDOT:PSS Multilayer Electrodes

Md. Maniruzzaman1, Mohammad Arifur Rahman2, Md. Abdul Kuddus Sheikh1,

Kyunghoon Jeong1, Ho-seok Nam1, Jaegab Lee1

1School of Advanced Material Engineering, Kookmin University2Department of Chemistry, University of Dhaka

Transparent conductive oxides (TCO), especially ITO has been widely used in thin film optoelectronic devices. But there

are technical and economic limitations for a large scale manufacturing of flexible devices. Recently, a triple layer electrode

consisting of a thin metal layer and two embedding transparent metal oxide layers (MoO3/Metal/MoO3) has been actively

researched to replace ITO. However, dissolution of the top MoO3 layer in PEDOT:PSS lowered the efficiency of solar cells.

A MoO3/Au/MoO3-PEDOT:PSS (composite) layer structure was developed as a transparent, low-resistance anode for use in

organic solar cells. Transmittance was maximized at 78% using 30 nm bottom MoO3 layers and 30 nm top MoO3-PEDOT:PSS

composite layer of a 12 nm Au layer. The series resistance, optical properties, work function of devices employing these

structures as anodes were tailored by varying the thickness and composition of the top MoO3-PEDOT:PSS composite

layer. Cells fabricated on MoO3/Au/MoO3-PEDOT:PSS multilayer electrodes showed a power conversion efficiency of

2.81%, comparable to that of ITO-based organic solar cells. The MoO3/Au/MoO3-PEDOT:PSS electrode was shown to be a

promising replacement of ITO for use in low-cost optoelectronic devices.


Selective Emitter PESC Crystalline Silicon Solar Cell

, , ,

Blue response emitter doping grid line

doping selective emitter . Boron doping CZ P-type Si wafer 180~200,

wafer . Shallow doping heavy doping sheet resistance cell

shallow doping heavy doping sheet resistance 120~130/, 60~70/

shallow doping heavy doping sheet resistance 80~90/, 40~50/ . Selective emitter

shallow doping Thermal wet oxidation(TWO) oxide layer Photo lithography

opening heavy doping . screen printing Al paste

, Nickel electroless plating LIP(Light induced plating) Copper electro plating

. Shallow doping heavy doping sheet resistance 20/

Rs 0.294 0.165 Voc 0.61V 0.63V Fill factor 69.97% 73.90%

. Efficiency 17.50% 18.37% .

050 ENGE 2013

[ENGE-023] Thermoelectric Materials and Devices

ZnO InGaO3(ZnO)2

, , ,

(2 )

3 . Ohta SrTiO3 SrTi0.8Nb0.2O3 c

(2 ) 2

. [1] Nomura InO2-() GaO+(ZnO)5( ) c InGaO3(ZnO)5

, InGaO3(ZnO)5

TFT (~80V-1s-1) . [2] InGaO3(ZnO)5

ZnO . [3] ZnO

InGaO3(ZnO)m

. InGaZnO c

ZnO ALD . ALD ZnO

. 100C, 150C, 200C (50nm) ZnO

InGaZnO . 900 9 .

, ZnO c . InGaZnO

, c 200C ZnO

InGaO3(ZnO)2 . , InGaO3 (ZnO)2

.

[1] H. Ohta, S. W. Kim, H. Hosono, Nature materials, 6 (2007) 129-134.

[2] K. Nomura, H. Ohta, K. Ueda, T. Kamiya, M. Hirano, H. Hosono, SCIENCE, 300 (2003) 1269-1271

[3] D. K. Seo, B. H. Kong, H. K. Cho, Cryst. Growth & Des., 10 (2010) 4638-4641


MoX2(X=S, Se, Te)

,

MoX2 graphene

. MoX2

. MoSe2/MoTe2

hot press . XRD (00l)

.

. ,

. MoSe2/MoTe2 ,

.



Carbon Nano Materials based Heat Dissipation Film for Super Thermal Conductivity

,

, ,

. .

matrix filler Aluminum nitride(AlN), Boron nitride(BN),

Aluminum oxide(Al2O3) filler .

. 1000W/mK

. filler BN

matrix epoxy resin - .


Chalcogenide CuGaX2 (X = Te, Se)

,

Chalcopyrite CuGaTe2 ZT=1.4 (950K) .

p-type 1.2eV , 1135K .

7.5 W/mK 6.7W/mK . CuGaTe2

CuGaS2 hot press . Hot press CuGaTe2

ZT (0.52, 650K). , 2 W/mK .

CuGaSe2 440 uV/K (3800 cm)

.


[ENGE-066] Flexible Displays and Printed Electronics

1, 1, 2

1 2

OLED , , Display . OLED

(Interlyer dielectic) RC deley .

. .

Fluorinated Silicate Glass(FSG), Hydrogen Silisesquioxane (HSQ), polyimide, Silk, Spin on SiO2, CVD SiO2

. (k

056 ENGE 2013


, RAHIM Abdur,

. Pentacene (C22H14)

PEDOT:PTS(conductivity = 650 S/cm)

. PES Al2O3/poly(4-vinyl phenol)(PVP) .

, 4% 3000 . 90 Peel

test PEDOT:PTS .

(Vth= -1.9V, Vth = 1.5V, Ion/Ioff ratio : 3.56E+5, =0.4 V-1s-1) . 4%

(Vth =-3.5V, Vth= 1.45V, Ion/Ioff ratio : 9.6E+4, = 0.28 V-1s-1) .


Hollow SiO2 Spheres with Polymer as a Low Dielectric Material

1, 2, 1

1 2

In modern semiconductor technology, with rapidly decreasing feature sizes and more demand for circuit speed, low-

the dielectric (k) have been inserted with Cu-interconnects to address the RC delay reduction, lowers power consumption,

and decreasing cross-talk between nearby interconnects. Alternatives for SiO2 with a lower dielectric constant are being

developed and introduced in main stream processing. In an attempt to lowering the dielectric constant, porosity is being

introduced into conventional dielectric materials. However there are some problems of porous material such as weakens

mechanical properties and adsorption of chemical species into the porous structure.

Here we report the synthesis of hollow SiO2 spheres to form a porous low k material. The polystyrene beads were used as

a sacrificial templates and a thin SiO2 layer was coated onto it using atomic layer deposition. The polystyrene beads were

successfully removed by calcination at 350 for 1 hour. SiO2 hollow spheres consist of about 200 nm hollow cores and 10 nm

SiO2 shell. We made the metal-insulator-metal structure to measure the dielectric constant of hollow SiO2 spheres covered

with PVP film. PVP was spin coated at 2000 rpm onto a hollow SiO2 spheres layer to form 580 nm thick. We compared the

dielectric constant at 1MHz of hollow SiO2 spheres covered with PVP films with pristine PVP film, pristine Al2O3 (18nm) film

and hollow Al2O3 spheres covered with PVP. SiO2 hollow spheres covered with PVP showed the lowest dielectric constant

among the other films. Furthermore, we used polyimide (PI) instead of PVP to reduce dielectric constant and increase thermal

resistance. It is believed that the present approach promises the alternative low dielectric material for modern semiconductor

technology.



, ,

KAIST

Nano-sized graphene dots precisely controlled by chemical or mechanical exfoliations are interesting in nanoelectronics

due to their quantum optical and electrical properties due to their quantum confinement. However, graphene is considered

to zero band gap material when it retains free of defect. The absence of band gap in graphene shows limitation in graphene

based optoelectronics; an isolated band gap is favourable to achieve sharp fluorescent peaks. In previous researches, most

of fabrications in controlled graphene quantum dots (GQDs) are performed by flak-type graphene in solutions. Nevertheless,

these methods are not a perfect solution to solve the uniform size and structure disorder problem. Accordingly, new strategy

for investigating size distribution and defect density is needed. Here we, reports fabrication process of size controlled GQDs

which have been patterned by self-assembled block-copolymer. The silica dot from polystyrene-b-polydimethylsiloxane

block copolymer served as etch barriers to further plasma treatment and lastly, hexagonally aligned GQDs in the diameters

of 10 nm and 20 nm were left on substrates. To confirm defect and oxygen contents effect in GQDs we measured the

photoluminescence peak and Raman peak shape. Subsequently, we found close correlation between luminescent property

and oxygen contents in GQDs and relatively weak correspondence to the luminescence with the size of GQDs.


Iodine Doped High Performance Flexible Pentacene TFTs

RAHIM ABDUR, Jeongeun Lim, Kyunghoon Jeong, Mohammad Arifur Rahman, Jaegab Lee

1Kookmin University2University of Dhaka

Large area flexible electronics is the critical issue for next generation devices. Pentacene is a good candidate as an active

layer for the flexible thin film transistors. To fabricate high performance flexible OTFTs, reducing the contact resistance

between pentacene and the contact electrodes is a vital issue. Iodine is an efficient acceptor for doping of pentacene,

increasing the conductivity as well as hole mobility in this material. Iodine doping in pentacene can also modify the interface

properties of source/drain and pentacene, thus resulting low contact resistance.

We have studied on the iodine doping of pentacene film, which was confirmed by Raman spectroscopy, revealing the

characteristic peaks of I3- and I5-. We also investigated the Iodine doping effect on the surface morphology, grain size, and

conductivity of the pentacene films with doping time from 30 seconds to several hours using atomic force microscopy and

four point probe respectively. Pentacene films grain sizes drastically increased with the doping time from an average value of

200 nm to 640 nm as a result of the facile movement of PEN+ free radicals, generated by iodine anions.

We also fabricated iodine doped source/drain contact pentacene TFTs on PES substrate, in which doping of iodine was

limited to source/drain contacts using novel structures. This doping in the contact area decreased the contact resistance as

well as increased the field effect mobility, thus leading to high performance flexible pentacene TFTs.

058 ENGE 2013


Laser Lift-off Transfer Printing of Patterned GaN LEDs from Sapphire to Flexible Substrates by using Cr/Au Laser Blocking Layer

1, 1, 1, 1, 2, 2, 1, 1

1Gwangju Institute of Science and Technology (GIST)2Korea Photonics Technology Institute (KOPTI)

GaN-based light-emitting diodes (LEDs) have been widely used for the high performance displays and solid-state lighting

systems due to high internal and external quantum efficiencies, low power consumption, and long-term stability. Recent

research suggests a methodology to generate flexible LED systems by transfer printing from sapphire to flexible substrates

through the laser lift-off (LLO) process. However, transfer printing of patterned GaN LEDs by LLO requires a cautious

approach to avoid unwanted damage on the polymer glue and supporting polymer layer formed between GaN LED chips.

This hampers a direct transfer printing of patterned GaN LEDs onto flexible substrates.

In this study, we develop a method to directly transfer the patterned GaN-based LEDs from sapphire onto flexible substrates

by the LLO process. Employing a Cr/Au metal layer as a laser blocking layer (LBL) prevents the penetration of intense

laser beam into the supporting polymer layers during the LLO process and enables direct transfer printing of the GaN LED

chips onto PET without significant damage on polymer glue and supporting polymer layers. In addition, we found that the

LBL enhances the sharp separation of the supporting polymer layer by being ablated under the exposure of laser beam.

Investigation of the residual elements on the separated sapphire substrate by scanning electron microscope and energy-

dispersive X-ray explains the microscopic process of sharp separation through the vaporization of the Cr/Au LBL metals

by the laser-induced ablation. Particularly, 22 23 LED arrays on a PET film with a high transfer yield of 95% and their

electroluminescence emission upon various bending configurations demonstrate the efficacy of this method for diverse

applications including next generation bio-medical/implantable optoelectronic systems and deformable displays.


Epoxy Composites by Using Non-oxidized Graphene Flakes with Non-covalelent Functionalization

, , ,

Graphene flakes (GFs) have excellent mechanical (~1 TPa) and thermal (~5,000 W/mK) properties, which can serve as

effective heat dissipation fillers in polymer nanocomposites[1-3]. However, homogeneous dispersion of graphene flaks in

polymer matrix, still preserving intrinsic material properties of graphene, isnt provided because of attractive van der waals

force between them[4]. Here, we present a novel approach to disperse non-oxidized graphene flakes using non-covalently

functionalization method. The graphene flakes functionalized by 1-Pyrenebutyric acid show the high dispersion ability in

various organic and aqueous solvents, which are even ready to be mixed with epoxy matrix. The prepared nanocomposites

of non-covalently functionalized and well dispersed GFs with epoxy present outstanding thermal conductivity (1.53 W/mK at

10 wt%) and mechanical properties (1.03 GPa at 1 wt%).


[ENGE-095] Flexible Electrode Materials and Ag Nano Wires

1

,

, , , .

.

trade-off . (Indium tin oxide)

. , .

, , .

.

. , ,

.

. . ,

. 25nm 5m

FDTD . 90%, 95% .

, .

Rayleigh anomaly, TE(transverse electric) cutoff, (Localized surface plasmon)

. 100nm TE cutoff . Rayleigh

anomaly .

. .

.

[ENGE-105] LED Materials and Devices

Enhanceced Phosphor Conversion Effieincy of GaN-based White Light-emitting Diodes Having Dichroic-filtering Contacts

1, 1, 1, E. Fred Schubert2, 3, 1

12Rensselaer Polytechnic Institute

3

White light-emitting diodes (LEDs) based on the combination of a GaN-based blue LED chip and a yellow phosphor layer

suffer from a low phosphor conversion efficiency (PCE) because a significant amount of the yellow fluorescence is emitted

towards the blue LED chip where the fluorescence is partially absorbed. In this study, we strongly enhanced the PCE of

a white LED by embedding a dichroic-filtering contact (DFC) which multi-functioned as a blue-transmitting but yellow-

reflecting optical filters, a

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