1. 1. Optimization for the fabrication of ternary halide perovskite solar cells via experimental design Kung, Chun-Hao
2. 2. Outline 2 Introduction Part I Using central composite design methods to find optimized fabrication process Part II Using mixture design of experiments on ternary halide perovskite device Conclusion
3. 3. 3 Exciton holes electronsLUMO HOMOInterface Exciton diffusion Charge separation Charge extraction Absorber Introduction General Perovskite unit(AMX3) Iodide (I) Methylammonium(MA) Lead (Pb) Advantages: Intense light harvesting Small exciton binding energy Long charge carrier lifetime Cost effective Disadvantage: Humidity-sensitive Toxicity MAPbI3
4. 4. Low procedure temperature All solution process Reference: Sun. et.al Energy Environ. Sci., 7, 399 (2014) 4 Solution process Reference: T.F Guo, Adv. Mater., 25, 3727 (2013) Evaporation process Structure-Conventional Planar heterojunction
5. 5. 5 Reference: Yi-Bing Cheng, Angewandte Chemie, 126, 10056 (2014) ITO PEDOT:PSS Perovskite(MAPbI3) PCBM Al Experimental
6. 6. 6 Reference: Michael Grtzel, Advanced Functional Materials, 24, 3250(2014) Effect of Annealing Temperature on Film Morphology of OrganicInorganic Hybrid Pervoskite Solid-State Solar Cells Temperature [C] Time Taken [h] PCE[%] 60 20 1.78 80 3 10.64 100 0.75 11.66 150 0.25 9.66 175 0.17 8.52 200 0.17 0.56 Interaction: Temperature & time Research purpose Part-I System: FTO/TiO2/MAPbI3-XClx/spiro-MeOTAD/Au System: ITO/PEDOT/MAPbI3/PCBM/Al Solvent washing
7. 7. 7 Reference: Alex K.-Y. Jen et.al Adv. Energy Mater,5, 1400960 (2014) Voc(V) Jsc(mA/cm2 ) FF (%) Eg MAPbI3 0.85 10.6 0.38 3.4 1.55 MAPb(I0.8Br0.2)3 0.88 10.9 0.38 3.6 1.65 MAPb(I0.6Br0.4)3 0.92 10.5 0.38 3.7 1.74 MAPbIXCl3-X 0.89 16 0.74 10.5 1.61 MAPb(I0.8Br0.2)XCl3-X 0.99 14.9 0.68 10 1.70 MAPb(I0.6Br0.4)XCl3-X 1.06 11.5 0.62 7.6 1.83 High-Performance Planar-Heterojunction Solar Cells Based on Ternary Halide Large- Band-Gap Perovskites Cl BrI Best recipe Research purpose Part-II Solvent washing method SystemITO/PEDOT:PSS/Perovksites/PC61BM/Bis-C60/Ag 90 C for 23 h
8. 8. 8 Create a fundamental fabricating process Suitable recipe for fabrication What is the main factor Extend single component to ternary system To find the best recipe To know the role of every componets 40 wt% Precursor solution/DMF Spin-coating Solvent washing Research purpose Drying First part: Annealing time and temp. Second part: Ternary halide precursor
9. 9. 9 Central composite design methods(CCD) Mixture design methods 40 wt% Precursor solution/DMFMethodology DOE: design of experiment 1. Annealing time and temp. 2. Ternary halide precursor
10. 10. Factorial Points : Estimated main factor & interaction Axial Points : Estimated pure quadratic form Center Points : Estimated pure Error 10 A tool to build a quadratic response surface for optimization Resolves both main effects and interactions Central composite design (CCD) Part I
11. 11. Level Temperature () Annealing time (mins) 120 5.0 1 115 6.5 0 100 10.0 -1 85 13.5 - 80 15.0 11 Run Temp. Time Temp. Time 1 -1 -1 85 13.5 2 -1 1 85 6.5 3 1 -1 115 13.5 4 1 1 115 6.5 5 0 0 100 10 6 0 0 100 10 7 0 0 100 10 8 0 - 100 15 9 0 100 5 10 - 0 80 10 11 0 120 10 Design matrix Reference: Michael Grtzel, Advanced Functional Materials, 24, 3250(2014) Effect of Annealing Temperature on Film Morphology of OrganicInorganic Hybrid Pervoskite Solid-State Solar Cells 120 5 mins 15 mins 8 100 Fixed parameters Solution : 40 wt% CH3NH3PbI3 Speed: 5 k r.p.m., 30 sec, Drip: Chlorobenzene at 4~6 secs(200ul)
12. 12. 1 1 2 2 3 3 4 4 4 4 5 5 5 5 5.5 5.5 5.5 5.5 5.5 5.5 6 6 6 6 6 6 6.5 6.5 6.5 6.5 6.5 7 7 7 7 7.2 Temperatuer(degree) Annealingtime(mins) 85 100 115 6.5 10 13.5 -1.5 -1 -0.5 0 0.5 1 1.5 -1.5 -1 -0.5 0 0.5 1 1.5 12 Parameter Coefficient Xtemp 1.16 Ytime -0.99 XtempXtemp -1.21 YtimeYtime -0.63 XtempYtime 0.99 Main factor: Interaction: Temp.-Time 90 110 PCE=6.78+1.16*x-0.99*y-1.21*x2-0.63*y2+0.98.*x*y > Regression of PCE (%)
13. 13. -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -20 -15 -10 -5 0 CurrentDensity(mA/cm 2 ) Voltage(V) 90 o c, 12 mins 105 o c, 12 mins 110 o c, 12 mins 13 Temp. time Jsc Voc FF PCE(%) 90 12 11.37 0.93 0.59 6.18 105 12 14.40 0.93 0.63 8.48 110 12 11.98 0.93 0.62 6.93 PCE contour plot Main factor: > Interaction: Temp.-Time Verification of PCE contour plot
14. 14. 14 It is consistent with UV-vis spectra result. Verification by UV-Vis Temp. time Jsc Voc FF PCE(%) 90 12 11.37. 0.93. 0.59. 6.18. 105 12 14.40. 0.93. 0.63. 8.48. 110 12 11.980.34 0.93. 0.62. 6.93. 400 500 600 700 800 0 1 2 3 Absorbance(a.u.) Wavelength(nm) 90oC,12mins 105oC,12mins 110oC,12mins -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -20 -15 -10 -5 0 CurrentDensity(mA/cm 2 ) Voltage(V) 90 o c, 12 mins 105 o c, 12 mins 110 o c, 12 mins
15. 15. 15 Temp. Crystal size 500nm , 12 mins , 12 mins , 5 mins , 12 mins Main factor is temperature. Verification by SEM
16. 16. Its effectively to find suitable parameters to fabricate perovskite device via CCD methods . The main factor affect the power conversion efficiency is temperature. 16 Summary Part I Drying Voc: 0.93 V Jsc:14.40 mA/cm2 FF:0.63 PCE:8.48 %
17. 17. Part II Using mixture design of experiments on ternary halide perovskite device to find best recipe 17
18. 18. PbI2 18 Cl- ITO PEDOT:PSS Perovskite PCBM Al Experimental section Br- I- Chloride, Bromide, Iodide Methylammonium(MA) Lead (Pb) Enhance morphology Enhance bandgap &stable phase +Fixed parameters Precursor solution : 40 wt% Speed: 5 k r.p.m., 30 sec, Drip: Chlorobenzene at 4~6 secs(200ul)
19. 19. 19 Model is fixed Algebra equation Time-consuming Model reduction SAS regression Interaction effect Save time 0.00 0.25 0.50 0.75 1.00 0.00 0.25 0.50 0.75 1.00 0.00 0.25 0.50 0.75 1.00 IBr Cl Binary Design (A) Ternary Design (B) Modified mixture design methods Reference: Scheffe (1958, 1963) introduced the simplex lattice designs and simplex-centroid designs.
20. 20. 20 Research methodology RegressionExperimental data Contour plot1. 2. 3. SAS 9.3 MATLAB R2013a 0.00 0.25 0.50 0.75 1.00 0.00 0.25 0.50 0.75 1.00 0.00 0.25 0.50 0.75 1.00 IBr Cl
21. 21. 0 20 40 60 80 Cl Br I Pb Atomic% Real Measured 0 20 40 60 80 Cl Br I Pb Atomic% Real Measured 0 20 40 60 80 Cl Br I Pb Atomic% Real Measured 21 The real mixing ratio is equal to the measured result. EDS analysis Cl:Br:I=0.67:0.17:0.17 Cl:Br:I=0.33:0.33:0.33 Cl:Br:I=0.00:0.00:1.00
22. 22. -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -15 -10 -5 0 0.00:0.00:1.00 0.00:1.00:0.00 1.00:0.00:0.00 0.00:0.75:0.25 0.17:0.67:0.17 CurrentDensity(mA/cm2) Bias (V) 22 J-V curve characteristic Part II rpm80 6000 MACl MABr MAI in DMF Spin-coating Ternary halide precursor Br I Cl Cl : Br : I
23. 23. 23 Jsc (mA/cm2) Voc (v) Bromide : Enhance Voc Cl Br I Cl Br I Jsc: Chloride & Iodide interaction Mixture Design contour plot
24. 24. 0.55 0.55 0.6 0.6 0.6 0.6 0.65 0.65 0.65 0.65 0.68 0.68 0.68 0.68 0.7 0.7 0.7 0.7 0.7 0.75 0.75 0.75 0.8 0.8 0.85 0.85 0.9 0.9 0 0.25 0.5 0.75 0 0.25 0.5 0.75 1 0 0.25 0.5 0.75 1 24 FF Cl Br I Chloride : Enhance FF Cl I 5 5 6 6 7 7 8 8 8 9 9 9 9 9 10 10 10 10 10 1111 11 11 12 12 12 12.5 12.5 12.7 0 0.25 0.5 0.75 0 0.25 0.5 0.75 1 0 0.25 0.5 0.75 1 Jsc (mA/cm2) Cl Mixture Design contour plot Jsc: Chloride & Iodide interaction
25. 25. -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -15 -10 -5 0 Currentdensity(mA/cm2) Voltage (V) 0.30: 0.15 : 0.55 0.30: 0.35 : 0.35 Cl : Br : I 0.30: 0.55 : 0.15 1 2 3 3 4 4 5 5 5 5 6 6 6 6 6 6.5 6.5 6.5 6.5 6.5 7 7 7 7.2 7.2 0 0.25 0.5 0.75 0 0.25 0.5 0.75 1 I 0 0.25 0.5 0.75 1 25 PCE Contour plot run Cl Br I Voc Jsc FF PCE 0.30 0.55 0.15 0.97 9.94 0.70 6.77 0.30 0.35 0.35 0.92 14.07 0.73 9.47 0.30 0.15 0.55 0.75 12.67 0.68 6.52 Cl IBr Verification by J-V curve
26. 26. 26 7 8 10 9 11 12 12.5 12.7 12 11 10 8 11 10 0 0.25 0.5 0.75 1 0 0.25 0.5 0.75 1 Cl Br I 0 0.2 0.4 0.6 0.8 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 5 6 7 8 9 10 11 12 1 0.98 0.94 0.9 0.85 0.8 0.75 0.85 0.8 0 0.25 0.5 0.75 1 0 0.25 0.5 0.75 1 Cl Br I 0 0.2 0.4 0.6 0.8 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0.7 0.75 0.8 0.85 0.9 0.95 1 0.6 0.65 0.68 0.7 0.75 0.8 0.850.9 0.55 0.7 0.7 0 0.25 0.5 0.75 1 0 0.25 0.5 0.75 1 Cl Br I 0 0.2 0.4 0.6 0.8 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.6 0.6 0.65 0.65 0.68 0.68 0.7 0.75 0.8 0.85 0.9 0.75 0.7 0.55 0 0.25 0.5 0.75 1 0 0.25 0.5 0.75 1 IBr Cl 5 6 6.5 7 7.2 7.2 7 6.5 6 5 6 6.5 0 0.2 0.4 0.6 0.8 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 JscVoc FF PCE Bromide Enhance Voc Chloride Enhance FF Cl BrI Best recipe Role of halides
27. 27. 400 500 600 700 800 0.0 0.2 0.4 0.6 0.8 1.0 Normalizedabsorbance(a.u.) Wavelength(nm) Cl Br I 0.30:0.15:0.35 0.30:0.35:0.35 0.30:0.55:0.15 400 500 600 700 800 0.0 0.2 0.4 0.6 0.8 1.0 Normalizedabsorbance(a.u.) Wavelength(nm) Cl Br I 1.00 0.00 0.00 0.00:1.00:0.00 0.00:0.00:1.00 27 Single component Ternary component Onset value Cl:800 nm Br:700 nm I:800 nm Bromide enhance Jsc ? Verification by UV-Vis spectra Bromide Enhance bandgap Enhance Voc
28. 28. 28 0 0.5 0.50.5 0 0.5 MACl MABr MAIMACl MABr MAI 0.17 0.67 0.170 0 1 More bromide, more pin holes 10m Verification by SEM Voc FFBr
29. 29. 29 Cl Br I 0.30 0.55 0.15 Cl Br I 0.30 0.35 0.35 run Cl Br I Voc Jsc FF PCE 0.30 0.55 0.15 0.97 9.94 0.70 6.77 0.30 0.35 0.35 0.92 14.07 0.73 9.47 0.30 0.15 0.55 0.75 12.67 0.68 6.52 Cl Br I 0.30 0.15 0.55 500nm Verification by SEM
30. 30. 10 15 20 25 30 35 40 45 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 Pure MAI Pure MABr Pure MACl 2Theta (degree) Intensity(a.u.) 10 20 30 40 50 0.30: 0.15 : 0.55 0.30: 0.35 : 0.35 Intensity(a.u.) 2Theta (degree) Cl : Br : I 0.30: 0.55 : 0.15 30 (110) (220) 14.1 28.4 * Diffraction peak: MAPbI3 : 14.1, 28.4, 43.3 MAPbCl3 : 15.88 MACl: 17.6, 35.3 MABr: 20.2, 30.3 PbI2 : 12.67, 25.34, 38.01 Verification by XRD MAClMABr PbI2
31. 31. 10 20 30 40 50 0.30: 0.15 : 0.55 0.30: 0.35 : 0.35 Intensity(a.u.) 2Theta (degree) Cl : Br : I 0.30: 0.55 : 0.15 31 (110) (220) 14.1 28.4 * Diffraction peak: MAPbI3 : 14.1, 28.4, 43.3 MAPbCl3 : 15.88 MACl: 17.6, 35.3 MABr: 20.2, 30.3 PbI2 : 12.67, 25.34, 38.01 Verification by XRD Reference: Yang Yang et.al Science,345, 6196 (2014) MAClMABr PbI2
32. 32. -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1E-5 1E-4 1E-3 0.01 0.1 1 10 CurrentDensity(mA/cm2) Voltage(V) 32 Cl : Br : I=0.30 : 0.35 : 0.35 Rs=78.23 /cm2 Rp=358.51 k/cm2 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -20 -15 -10 -5 0 P:100mW/cm 2 Voc:0.92 V Jsc:14.07 mA/cm 2 FF:0.73 PCE:9.47% Dark Light CurrentDensity(mA/cm2) Voltage(V) Best recipe Fixed parameters Solution : 40 wt% (MACl+MABr+MAI)+PbI2 Speed: 5 k r.p.m., 30 sec, Drip: Chlorobenzene at 4~6 secs(200ul)
33. 33. 33 It has been known the role of halide in ternary perovskite solar cells via design of experiment. It is obtained the best recipe with proper mixing ratio via design of experiment. Summary Part II Ternary halide precursor Voc: 0.92 V Jsc:14.07 mA/cm2 FF:0.73 PCE:9.47 % Cl : Br : I=0.30 : 0.35 : 0.35
34. 34. It is successfully to employ CCD and mixture design methods to find optimized recipe on ternary perovskite solar cells. 34 Know situation Design of experiment Optimized process Conclusion Voc: 0.93 V Jsc:14.40 mA/cm2 FF:0.63 PCE:8.48 % Voc: 0.92 V Jsc:14.07 mA/cm2 FF:0.73 PCE:9.47 %
35. 35. Thank you for your listening. 35