2017.11.2 5SPring-8 /19SPring-8

FET

FET

()

(, tan )

KEK Photon Factory)

()

(, tan )

KEK Photon Factory)

FET

20

0 100 200 300 400

0.6

0.7

0.8

0.9

|ID

| (

A)

time (s)

OTFT

0.1 0.4 0.6 0.8

1.0 h (mm)

4

4

TFT

()

AFM image

100m

Optical micrograph

Au Au

SiO2 surface

(BEDT-TTF)(TCNQ) crystal Au electrode

11

Typical dimensions 0.83000.4 m

c-axis

(or)

Si

1. BEDT-TTF and TCNQ are dissolved in chloroform (in dry N2 atmosphere).

2. Mix these solutions.

3. Drop the solution onto SiO2/Si substrate and vaporize the solvent very slowly.

4. Dry the sample in vacuum to remove the residual solvent.

SiO2(300nm)/Si substrate

Crystal growth by a cast method

Au/Cr

electrodes

Au/Cr

electrodes

SiO2

surface

direction of droplet shrink

100m

vaporize

5 times speed movie

AFM image

Au

Au

SiO2 surface

ET-TCNQ crystal

W: 0.8 m

L: 300 m

H: 0.4 m

Typical

dimension

5 10 15 200

2000

4000

6000

8000

2 (degree)

INT

EN

SIT

Y (

counts

/sec)

XRD

X-ray diffraction pattern

(BEDT-TTF)(TCNQ)

(100)

(200) (300)

(010)

(400)

(001)

5 10 15 200

1000

2000

3000

2 (degree)

INT

EN

SIT

Y (

counts

/sec)

(BEDT-TTF)(TCNQ)

(100)

(200)

(300) (400)

b-c()

a () T. Mori et al. Solid State Commun., 59, 355 (1986).

TCNQ

BEDT-TTF

XRD(X )

FET

TCNQ layer

BEDT-TTF layer

long axis of crystal

(c-axis)

SiO2/ Si substrate

a

b c

electric current

Top view

long axis

of crystal

Side view

direction of

electric current flow

long axis of crystal

()

(, tan )

KEK Photon Factory)

FET

Source

SiO2(300nm)/Si substrate

highly-doped n-type

(BEDT-TTF)(TCNQ) crystal

A

Drain

Gate

Au/Cr electrode

gap20m

-50 -40 -30 -20 -10 0-3

-2

-1

0

Drain-Source Voltage (V)

Sourc

e C

urr

ent

(A

)

0-20-40-60-80

VGS (V)

318K

0 10 20 30 40 500

1

2

3VGS (V)

80604020 0

Drain-Source Voltage (V)

Sourc

e C

urr

ent

(A

)

308K

(BEDT-TTF)(TCNQ)FET

Gate

Source Drain

hole injection

Source Drain

Gate

Source Drain

Gate

pinch off electron injection

electron linear region hole

electron saturation hole

hole abrupt increase electron

VGS > 0 VGS < 0

-20 -10 0 10 200

10

20

30

40

Sourc

e C

urr

ent (

nA

)

230KVDS = 5V

f = 8 Hz

-20 -10 0 10 20

250K

-20 -10 0 10 20

280K

-20 -10 0 10 20

290K

-20 -10 0 10 20

320K

-20 -10 0 10 20

Gate-Source Voltage (V)

340K GS

S

DS

FE

V

I

VWC

l

i

220 240 260 280 300 320 3400

1

2

3

e

h

Fie

ld E

ffect

Mobili

ty (

1

0-2

cm

2/V

s)

Temperature (K)

TMI

SiFET

Source Drain

Gate A

-20 -10 0 10 200

10

20

30

40290 K

Gate - Source Voltage (V)S

ourc

e C

urr

ent (

nA

)

-20 -10 0 10 20

-50

0

50

Sourc

e C

urr

ent

(nA

)

Gate-Source Voltage (V)

VDS = 5V VDS = 0V 2

300K f = 3Hz

VDS = 0V

VDS 0V

dt

dQI

driftIdt

dQI

displacement current

displacement current + drift current

FET

difference

FET

GS

S

DS

FE

V

I

VWC

l

i

-20 -10 0 10 20

-50

0

50

Sourc

e C

urr

ent

(nA

)

Gate-Source Voltage (V)

VDS = 0V

300K

f = 3Hz dt

dQI

t IdtTTQ 21

Vt dVdtdVI

dtdt

dQQ

ET-TCNQ crystal

220 240 260 280 300 320 3400

1

2

3

e

h

Fie

ld E

ffect

Mobili

ty (

1

0-2

cm

2/V

s)

Temperature (K)

200 220 240 260 280 300 320 3400

1.0

2.0

Temperature (K)

Ele

ctr

on M

obili

ty

( 1

0 -

2

cm

2/

Vs)

330K210K

210K330K

330 K 210 K

210 K 330 K

I III

II IV

TMI

Tc1

-20 -10 0 10 20

-50

0

50

Sourc

e C

urr

ent

(nA

)

Gate-Source Voltage (V)

VDS = 0V

300K

f = 3Hz

t IdtTTQ 21

Vt dVdtdVI

dtdt

dQQ

T

I

200 250 300

80

81

82

Temperature (K)

Dis

pla

cem

ent C

urr

ent (

nA

)

VGS=20V

VDS=0V

f=3Hz

Tc1

Q

200 250 3001070

1080

1090

1100

1110

Temperature (K)

Dis

pla

cem

ent

Curr

ent

(nA

)

VGS=80V

VDS=0V f=10Hz

-50 0 50

(255K) - (245K)

-50 0 50

(310K) - (300K)

-50 0 50

-1.0

0

1.0

Gate-Source Voltage (V)

(200K) - (190K)

Q

(

10

-10 C

)

-50 0 50

(230K) - (220K)

Tc1

()

(, tan )

KEK Photon Factory)

(BEDT-TTF)(TCNQ)

SiO2 Si

Au

A

VGp

D S

G E

A

C

C

FET

(Fi-TSC)

VD

TSC

Au

UHB

LHB (BEDT-TTF)(TCNQ)

SiO2 Gate

VGP >0 VG

P =0 EF

VGP

TSC

TSC

VGP

VD0V

VG

p

VD

Sam

ple

tem

pera

ture

0V

0V

300K

Time

320K

280K

90K

200K

Ferroelectric-like

Phase

Poling Measuring

6K/min

30min 15min

Fi-TSC

280KVGP15

90K

VGP0V(6K/min)TSC

120 160 200 240 280 320

-40

-20

0

20

40

30 V

0 V

-30 V

TS

C /

heating r

ate

(pC

/K)

Temperature (K)

VGP

Fi-TSCVGP

dt

dTSp

dt

dT

dT

dPS

dt

dPSI rr

S : , Pr : , p = dPr / dT :

E S

()

120 160 200 240 280 320

-40

-20

0

20

40

30 V

0 V

-30 V

TS

C /

heating r

ate

(pC

/K)

Temperature (K)

VGP

Fi-TSCVGP

VGP TSC

TSC

-250

-200

-150

-100

-50

0

Temperature (K)

TS

C /

heating r

ate

(pC

/K)

VGP :

0 V

- 20 V

- 40 V

- 60 V

180 200 220 240 260 280 300 320

1.92

1.93

1.94

Capacitance (

nF

)VG

P

VGP TSC

285K

TSC

()

(, tan )

KEK Photon Factory)

-10.0000 10.0000X (micron)

-1.0000

20.0000

Y (micron)

File prefix: ET-TCNQ3.EOU

Plot type: Filled contour

Quantity: |D|

CONDFLAG: 0.0000E+00

Minimum value: 0.0000E+00

Maximum value: 3.4552E-03

2.4186E-04

4.8372E-04

7.2558E-04

9.6745E-04

1.2093E-03

1.4512E-03

1.6930E-03

1.9349E-03

2.1768E-03

2.4186E-03

2.6605E-03

2.9023E-03

3.1442E-03

3.3861E-03

5.0 - 5.0 Position (m)

Source electrode

organic crystal

Si substrate

SiO2 gate insulator

(BEDT-TTF)(TCNQ)

SiO2

Si

(FEM)

(CG)(CG) (BEDT-TTF)(TCNQ)

()

0.2 0.4 0.6 0.8

0.2

0.4

0.6

0.8

0

'Co (nF)

"C

o (

nF

)

300K 280K 260K

320K 340K

110824#1(crys.)280K 110824#1(crys.)240K 110824#1(crys.)200K 110824#1(crys.)160K

with cryo.

0.002Hz

C1

C2

R1

R2

(C2,R2)

(C1,R1) (BEDT-TTF)(TCNQ)*

C1= 0.87 nF

C2= 1.6 nF

R2= 40 G

(C2,R2)

(C1,R1)

0

0.05

0.10

0.15

C

(nF

)

300K

280K

260K

340K

(a)

10-2 10-1 100 101 102 103

0

0.01

0.02

Frequency (Hz)

tan

260 K

280 K 300 K

320 K

(b)

285K

285 K

c

b

1 1

(TMI=320K)

H. Seo et al. JPSJ, 76, 013707 (2007)

1/4-filled 1D

0

1

2

3

e

h

(

10

-2 c

m2/V

s)

1.94

1.96

1.98

Temperature (K)

C (

nF

)

Ferroelectric

Paraelectric

0

0.5

1.0

1.5

bulk (

10

-4 S

/m)

Mott insulator (bulk)

Metallic (bulk)

(

10

-4 S

/m)

220 240 260 280 300 320 340 3600

1

2

Temperature (K)

Index n

VG = 40 V VG = 80 V

I V n

uniform

charge ordered

(CO) state

dimer Mott

insulator

(DM) DM+CO ferroelectric

metallic state

TMI

TC1

TC2

CO

()

(, tan )

KEK Photon Factory)

Si

100m

X

KEK BL-8B

Si

1

free standing

100m

N2

free standing

(BEDT-TTF)(TCNQ) (295K)

200 300

1160

1180

1200

1220

Temperature (K)

Volu

me (

3)

7.70

7.80

7.90

Length

(

)

b axis

200 300

90

95

100

105

Temperature (K)

Angle

(d

egre

e)

23.89

23.90

23.91

23.92a axis

6.60

6.65

6.70c axis

FETXRD

(200)

(2-10)

(2-21)

(400)

(4-10) (6-10)

(221)

(210) (410)

2a

-b 200 300

3.45

3.50

3.55

Temperature (K)

d (

2-2

1)

(

)

FET d(2-21)

d(2-21)

FET

Si

a

c

FET

BEDT-TTF

TCNQ

200 300

11.7

11.8

11.9

12.0

Temperature (K)

d (

200)

(

)

FET d(200)

d(200)

FETd (hkl)

200 300

6.30

6.40

6.50

Temperature (K)

d (

2-1

0)

(

)

FET d(2-10)

d(2-10)

FET

FET

a

b

c

, ,

b, c,

a, ,

200 300

3.45

3.50

3.55

Temperature (K)

d (

2-2

1)

(

)

200 300

11.7

11.8

11.9

12.0

Temperature (K)

d (

200)

(

)

200 300

6.30

6.40

6.50

Temperature (K)d

(2-1

0)

(

)

a = 23.7 (135Ka99.16%) b = 7.78 (135Kb101.06%) c = 6.63 (135Kc100.52%)

= 104.0(135K99.14%) = 96.5 (135K101.44%) = 89.3 (135K100.45%)

b a() d(hkl)CO

FET

285K

bFET

XRD()FET