臺灣博碩士論文加值系統

本研究首先整理目前有機金屬鹵化鈣鈦礦太陽能電池（Organometallic Halide Perovskite Solar Cells, Omh-PSC）的重要議題。該電池在效率和穩定性的兩個關鍵領域都以指數式地快速增長。2016年底，電力轉換效率（PCE）已達到23.6％。雖然技術現況壽命已可達數千小時，令人對其前景樂觀，不過其穩定性仍限制了實際應用可能性。目前的改進都是通過運用不同的材料，優化界面和元件結構來實現，特別是導入碳電極取代電洞導體的中孔元件，使其具有穩定，低成本和易於製造。然而，改善工作仍需持續，因有機金屬鹵化鈣鈦礦材料劣化，界面和元件不穩定性等問題仍存在。而要突破有機金屬鹵化鈣鈦礦材料的穩定性和實現戶外實際應用，就需要全面了解這些問題。仍本研究首先綜合性地探討元件失效和材料退化的後果，以及造成其劣化的機制，研提改進穩定性的方法。此理解有助於本研究後續的發展: (1)綠色及可放大的材料合成方法及其結構，以及其結構與特性間的關係與表徵；(2)利用光致發光(Photoluminescence, PL)，探討雷射照射和熱處理對於材料之載子動力學的控制和影響；(3)為改善材料之化學穩定性，另運用計算方法設計以一價陽離子取代甲基銨陽離子，獲得完全無機鈣鈦礦材料。

The existing issues in this area of organometallic halide perovskite solar cells (Omh-PSC) were first reviewed in this work. Omh-PSCs have evolved in an exponential manner in the two key areas of efficiency and stability. The power conversion efficiency (PCE) reached 23.6% in late 2016. The key disquiet was stability, which has been limiting practical applications, but now is in a promising state of the art, measured in thousands of hours. These improvements have been achieved with the application of different materials, interfaces and device architecture optimizations, especially after the investigation of hole conductor free mesoporous device, incorporating carbon electrodes, which promise stable, low cost and easy device fabrication methods. However, this work is still far from complete. A comprehensive understanding of these issues is required to achieve stability breakthroughs and practical outdoor applications for Omh-PSCs. The causes of failure and associated mechanisms of device degradation followed by the origins of degradation, approaches to improve stability, and methods and protocols are discussed in detail. Therefore, this work helps us conduct the following work on (1) material facile and scalable synthesis methods and characterization of its structure-property relationships; (2) understanding of the PL lifetime as a function of photoexcited state dynamics using laser light irradiation and thermal treatment as controlling parameters for the study. And (3) development of new perovskites material using computational methods and suggesting some promising fully inorganic perovskites materials with metal(I) cation replacing methylammonium cation.

Abstract ix
Acknowledgment xiii
TABLE OF CONTENTS xv
LIST OF FIGURES xix
LIST OF TABLES xxiv
LIST OF SCHEMES xxv
LIST OF ACRYNOMES AND SYMBOLES xxvi
1. Research Background 1
1.1 Historical background 1
1.2 Perovskite Phenomena 3
1.3 CH3NH3PbI3 Perovskite and fundamental origin of this research 7
1.4 Optical characterization 13
1.5 Organization of this thesis 15
2. Thesis dissertation 17
2.1 Motivation of this study 17
2.2 Aims and objectives of the study 20
3. Literature review on Organometal halide perovskite solar cells: degradation and stability 23
3.1 Background 23
3.2. Overview of Omh-PSCs Devices 25
3.1.1 The need for Omh-PSCs 25
3.1.2 Mechanistic processes in Omh-PSCs 26
3.1.3. Current status of performance in Omh-PSCs 28
3.3 Causes of failure and associated mechanisms of degradation 39
3.3.1. Oxygen induced degradation 41
3.3.2 Light induced degradation 44
3.3.3 Moisture induced degradation 45
3. 3.4 Temperature induced degradation 48
3.3.5 Thermal and electric field induced intrinsic degradation 49
3.4. Origins for degradation of Omh-PSCs 53
3.4.1. Effects of device components 53
3.4.2 Effect of device architecture 64
3.4.3 Effect of interface 69
3.5. Suggested approaches to improve stability of Omh-PSCs 71
3.5.1 Omh-perovskite material aspects 71
3.5.2 Device architecture aspects 72
3.5.3 Interface aspect 74
3.5.4 Device operation aspect 77
3.6. Protocols and methods for studying degradation mechanisms 80
3.6.1 Possible methods for studying degradation of Omh-PSCs 80
3.7. Summary and prospects 84
4. Experimental section and characterization methods 89
4.1 CH3NH3PbI3 Film preparation: 89
4.2 Characterization methods 89
4.2.1 Steady State Photoluminescence (PL) and Time-Resolved PL (TRPL) Measurement 90
4.2.2 In-situ Micro-Raman Spectroscopy 92
4.2.3 In Situ synchrotron X-ray diffraction during heating process 94
4.2.4 Angle dispersive X-ray diffraction 94
4.2.5 In-situ X-ray Absorption Spectroscopy 95
4.2.6 X-ray Absorption Spectroscopy Data Analysis 97
4.2.7 Scanning electron microscopy 99
4.2.8 Atomic Force Microscopy 99
4.2.9 Computational method 99
5. Scalable Synthesis of Highly Crystalline CH3NH3PbI3 at Room Temperature in Acetonitrile: the Reactive crystallization of CH3NH3PbI3 101
5.1 Introduction 101
5.2 Optical properties 103
5.3 Nature, reaction and formation mechanism of the synthesized nanocrystals in Acetonitrile: 105
5.4 Nucleation and growth mechanisms of perovskite in DMSO and DMF solvents using acetonitrile as anti-solvent studied by Angle Dispersive X-ray Diffraction 111
5.5 Effect of CH3NH3+ cation on the preferred orientation of CH3NH3PbI3 121
5.6 Higher temperature structural coexistence and its impact on PL lifetime 124
5.7 Thermal behavior and degradation mechanisms of CH3NH3PbI3 129
5.8 Summary 131
6. Nanosecond Pulse Laser irradiation induced reduction of disorder, heterogeneity and non-radiative recombination in organolead halide hybrid perovskite thin film 133
6.1 Introduction 133
6.2 Physical origin behind disorder and film heterogeneity 134
6.3 Mechanisms of microstructure reconstruction and restructuring-Steady state PL 137
6.4 Mechanisms of microstructure reconstruction and restructuring-micro Raman and Angle dispersive X-ray diffraction 140
6.5 In-situ XAS study of local disorder and structural evolutions in thermal and laser light treated CH3NH3PbI3 thin films 148
6.6 CH3NH3PbI3 film morphology evolution by AFM and SEM 153
6.7 Summary 158
7. Development of Transition metal (I) cation based New Inorganic Perovskites for optimal light absorption 161
7.1 Introduction 161
4.3 Crystal structures/Geometric properties 163
7.3 Electronic and optical properties of APbX3 perovskites 166
7.4 Effect of A and X Size on optical bandgap of APbX3 perovskites 170
7.5 Summary 174
5 General conclusions 175
6 Perspectives 179
References 183
Appendix A Supplementary result for Chapter 5 211
Appendix B Supplementary result for Chapter 6 221
Appendix C Supplementary result for Chapter 7 235
Curriculum Vitae 241
Summary of research papers 243
List of conference papers 245
List of conference awards for this research 247

1. Poster ise152085 Laser Induced Degradation Study of CH3NH3PbI3 Light Harvesting Oih-Perovskite Semiconductor, 66th Annual meeting of The International Society of Electrochemistry (ISE 2016)
2. Poster-NSRRC Users’ Meeting no. 46 In-situ Structural Characterization of CH
3NH3PbI3 Nano-crystalline Materials Using Synchrotron-radiation Techniques, The 22nd Users’ Meeting and Workshops (2016)
3. Oral presentation2016ICEGT- In‐situ Structural Characterization of CH3NH3PbI3 Nano‐crystalline materials using Synchrotron‐Radiation Techniques, 2016 1st International Conference on Green Energy Technology (ICGET 2016)