Title Page
Abstract
Contents
Chapter 1. Introduction 16
1.1. Organic Semiconductors 16
1.1.1. Perovskite Solar Cells 17
1.1.2. Organic Field-Effect Transistor 32
1.2. Sulfur or Nitrogen containing Heteroacenes 39
1.2.1. Solution processable Small Molecules 40
1.2.2. Alkyl chains and Oligoethylene glycol chains 44
1.3. Research Proposal 47
1.4. Reference 49
Chapter 2. Engineering length of ethylene glycol chains on indolo[3,2-b]indole-based small molecules as dopant-free hole transporting materials for inverted (p-i-n) and conventional (n-i-p) perovskite solar cells 54
2.1. Introduction 54
2.2. Experimental 60
2.3. Result and Discussion 74
2.3.1. inverted (p-i-n) perovskite solar cells 74
2.3.2. conventional (n-i-p) perovskite solar cells 93
2.4. Conclusion 115
2.5. Reference 116
Chapter 3. Aqueous-alcohol-processable indolo[3,2-b]indole-based crystalline small molecules for organic field effect transistors with Penta-ethylene glycol side chains 121
3.1. Introduction 121
3.2. Experimental 124
3.3. Result and Discussion 129
3.3.1. Material synthesis, optical, electrochemical, and thermal characteristics 129
3.3.2. Structual Analyses of HTM 134
3.3.3. Solution-Processed OFET Characteristics 143
3.4. Conclusion 148
3.5. Reference 149
Abstract in Korean 151
List of Publication 156
List of Presentation 158
List of Patents 159
Table 2.1. Optical and electrochemical characteristics of the DEG-IDIDF. 80
Table 2.2. The best-performing photovoltaic performance of the PSCs including each PEDOT:PSS, IDIDF, and DEG-IDDF HTM. 92
Table 2.3. Photovoltaic performance of the DEG-IDIDF PSC devices under various thermal annealing 92
Table 2.4. Photovoltaic performance of the MAPbI₃ based PSCs devices including different HTMs 97
Table 2.5. Photovoltaic performance of the FAPbI₃ based PSCs devices including doped and undoped TEG-IDIDF 97
Table 2.6. Optical and electrochemical characteristics of TEG-IDIDF, together with the hole mobility acquired by the and SCLC. 103
Table 2.7. SC-XRD, GIWAXS, and out-of-plane XRD patterns of the TEG-IDIDF and clearly identifying the (002) and (004) peaks of TEG-IDIDF 107
Table 3.1. Solubility (mg mL-1) of the PEG-IDIDF in various solvents at room temperature[이미지참조] 133
Table 3.2. Optical and electrochemical characteristics of the IDIDF and PEG-IDIDF 133
Table 3.3. Summarize d-spacing parameters of the IDIDF, and PEG-IDIDF films processed with the CF solvent and FWHM values of the first peak of XRD... 142
Table 3.4. OFET device performance of IDIDF, and PEG-IDIDF film processed by CF solvent 147
Table 3.5. OFET device performance including the PEG-IDIDF film processed from Ethanol and various ethanol water co-solvents 147
Figure 1.1. Crystal structure of ABX₃, and extended strcutre of perovskite 20
Figure 1.2. Structure of Perovskite solar Cells (conventional and Inverted) 21
Figure 1.3. Schemetic diagram of conventional and inverted perovskite solar cells operation 23
Figure 1.4. Current density-voltage curve of solar cells and photovoltaic parameters represented in current density-voltage curve. 23
Figure 1.5. Molecular structure of Spiro-OMeTAD, and dopants: lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), tert-butylpyridine (t-BP), and... 28
Figure 1.6. Molecular structure of spiro-based, diphenylamine containing, and heteroacenes hole transport materials with dopants 30
Figure 1.7. Various molecular structures of dopant-free HTMs 31
Figure 1.8. Various configurations of organic field effect transistors. (A) Bottom gate Top contact, (B) Bottom gate Bottom contact, (C) Top gate... 35
Figure 1.9. OFET working conditions and corresponding current-voltage characteristics: linear regime condition; start of saturation regime at pinch-off;... 36
Figure 1.10. Representative current-voltage characteristics of an OFET: (A, B) transfer characteristics in both regimes (linear/saturation) and output... 36
Figure 1.11. Chemical structure of Acenes and their derivatives 38
Figure 1.12. Packing structure of sulfur or nitrogen containing heteroatoms elucidated by single crystal crystallography 42
Figure 1.13. Schematic of small molecules during the coating process 43
Figure 1.14. Schematic characteristics of OEG chains: high polarity, highflexibility and ionic conductivity. 46
Figure 2.1. Chemical structures of DEG-IDIDF 76
Figure 2.2. UV-vis absorption spectra of the DEG-IDIDF in solution and film states 76
Figure 2.3. Transmittance dependence of DEG-IDIDF films on solution concentrations for film casting 77
Figure 2.4. Cyclic voltammograms (CVs) of IDIDF and PEG-IDIDF (with ferrocene) 78
Figure 2.5. DSC and TGA curves of DEG-IDIDF 79
Figure 2.6. Single-crystal analysis of DEG-IDIDF and IDIDF 83
Figure 2.7. GIWAXS patterns of films of DEG-IDIDF and IDIDF 84
Figure 2.8. GIWAXS patterns of films of DEG-IDIDF with thermal annealing RT, 100 ℃, and 120 ℃ 84
Figure 2.9. SCLC mobility of DEG IDIDF and IDIDF 86
Figure 2.10. Steady-state PL spectra of IDID derivatives based perovskite films. 86
Figure 2.11. Time-resolved PL spectra of IDID derivatives based perovskite films. 87
Figure 2.12. J-V characteristics of the best-performing devices with PEDOT:PSS, IDIDF, and DEG-IDIDF as HTMs 90
Figure 2.13. PCE histograms of over 20 devices and reverse and forward scans of the champion devices based on DEG-IDIDF 90
Figure 2.14. EQE spectra of the best performing PSC 91
Figure 2.15. Air and thermal stability of HTMs based PSCs 91
Figure 2.16. J-V characteristics of the MAPbI₃ based devices with undoped Spiro-OMeTAD, IDIDF, and TEG-IDIDF 95
Figure 2.17. Reverse and forward scans of the champion devices based on TEG-IDIDF 95
Figure 2.18. PCE histograms of over 17 devices of TEG-IDIDF 96
Figure 2.19. J-V characteristics of the FAPbI₃ based PSCs with doped and undoped TEG-IDIDF 96
Figure 2.20. UV-vis absorption spectra of the TEG-IDIDF in solution and film states 100
Figure 2.21. Photoelectron spectroscopy analyses of Spiro-OMeTAD and TEG-IDIDF 101
Figure 2.22. Cyclic voltammograms of Spiro-OMeTAD and TEG-IDIDF with ferrocene 101
Figure 2.23. Energy level diagrams of the PSCs device including Spiro-OMeTAD and TEG-IDIDF 102
Figure 2.24. DSC and TGA analyses of TEG-IDIDF 102
Figure 2.25. SC-XRD analysis of TEG-IDIDF and GIWAXS analyses of Spiro-OMeTAD and TEG-IDIDF 106
Figure 2.26. Out-of-plane XRD of the TEG-IDIDF 106
Figure 2.27. Stead-state PL quenching and TCSPC PL measurements of bare Perovskite film and each HTM (doped Spiro-OMeTAD and undoped TEG-... 109
Figure 2.28. Efficiency features of the PSC devices containing the TEG-IDIDF and doped-Spiro-OMeTAD HTMs under 60 % RH. 112
Figure 2.29. GIWAXS analyses of the device with Pervskite/undoped TEG-IDIDF under constant humidity (RH 65) taken for 50 days and their... 113
Figure 2.30. GIWAXS analyses of the device with Pervskite/doped Spiro-OMeTAD under constant humidity (RH65) taken for 3 days and their... 113
Figure 2.31. Thermal stability of the PSCs device with undoped TEG-IDIDF 114
Figure 3.1. Normalized UV-visible absorption spectra of the PEG-IDIDF molecules in solution and film state. 131
Figure 3.2. Cyclic voltammograms (CVs) of IDIDF and PEG-IDIDF (Inset: CV of ferrocene) 132
Figure 3.3. TGA curves of PEG-IDIDF 132
Figure 3.4. DSC analysis of PEG-IDIDF 132
Figure 3.5. AFM topography images (2 μm x 2 μm) of the PEG-IDIDF films processed from various solvents 138
Figure 3.6. Optical images of the PEG-IDIDF films processed from various solvents 139
Figure 3.7. Photographic image of PEG-IDIDF (8mg/mL) solutions 140
Figure 3.8. Out-of-plane XRD spectra of the IDIDF and PEG-IDIDF processed with CF and Out-of-plane XRD spectra of the PEG-IDIDF processed with... 140
Figure 3.9. GIWAXS patterns and out of plane line-cuts of the IDIDF, PEG-IDIDF processed with CF, and PEG-IDIDF processed with ethanol water co-... 141
Figure 3.10. Transfer and output characteristics of the IDIDF and PEG-IDIDF processed with CF 145
Figure 3.11. Transfer and output characteristics of the PEG-IDIDF processed with Ethano:Water (90:10) 146
Figure 3.12. Diverse solvent-dependent mobility of the PEG-IDIDF OFETs. 146
Scheme 2.1. chemical structures of DEG-IDIDF 73
Scheme 2.2. chemical structures of DEG-IDIDF 73
Scheme 2.3. chemical structures of TEG-IDIDF 73
Scheme 3.1. chemical structures of TEG-IDIDF 128