Utilization of semiconducting polymer nanowires for performance improvement of bulk heterojunction organic solar cells
- 주제(키워드) Organic solar cells , Polymer nanowires
- 발행기관 아주대학교
- 지도교수 이순일
- 발행년도 2017
- 학위수여년월 2017. 2
- 학위명 박사
- 학과 및 전공 일반대학원 에너지시스템학과
- 실제URI http://www.dcollection.net/handler/ajou/000000025012
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
We developed a stable poly(3-hexylthiophene) (P3HT) nanowire (NW) dispersion solution and applied it to various organic solar cells (OSCs) effectively. In addition, we characterized the interfacial morphology of active layers (ALs) with P3HT NWs and found that they contribute significantly to light absorption. With the inclusion of P3HT NWs in ALs, OSCs based on P3HT donor and indene-C60 bisadduct (ICBA) acceptor showed power conversion efficiency (PCE) improvements for both bulk hetero junction (BHJ)- and bilayer (BL)-structure AL devices. The PCE increase was ~14% for both types of P3HT:ICBA OSCs. The variations in FF with respect to Voc and the equivalent-circuit parameters based on a non-ideal diode model have been discussed. We demonstrated a 47.1% efficiency improvement resulting from the combination of device-architecture modification and the inclusion of P3HT NWs in BHJ ALs. The modeling of ellipsometry spectra showed substantial changes in inhomogeneity and optical constants of the BHJ ALs with the inclusion of P3HT NWs. The operating characteristics of the nominal BL OSCs, the ALs of which consisted of sequentially cast bottom P3HT donor and top ICBA acceptor layers, resembled those of the OSCs with BHJ ALs. Optical analysis and device simulations showed that such resemblance could be attributed to the similarity in micromorphology of the ALs. Separate assessments of the exciton generation and the charge-carrier transport and/or extraction revealed that the contribution of P3HT NWs was more prominent in optical effects.
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Table of contents
Abstract i
Table of contents ii
List of Tables xii
Chapter 1 1
Introduction 1
1.1 Overview 1
1.2 Solar energy 2
1.3 Organic solar cells 4
1.3.1 Poly(3-hexylthiophene) (P3HT) 5
1.3.2 P3HT nanowires (P3HT NWs) 6
1.3.3 P3HT based OSCs including P3HT NWs 7
1.4 Structure of organic solar cells 9
1.5 Working principles of organic solar cells 10
1.5.1 Power conversion efficiency (PCE) of solar cells 10
1.5.2 Principle of photoelectric conversion 14
1.6 Optical simulation 16
1.7 Outline for thesis 17
Chapter 2 19
Experimental Procedure 19
2.1 Preparation of P3HT NWs solution 19
2.2 Synthesis of ZnO sol-gel for inverted type OSCs 20
2.3 Common process for device fabrication 20
2.4 Formation of BL and BL-NW DA layers 21
2.5 Formation of the DA layers in BHJ devices 22
2.6 Modeling Analysis of Ellipsometry Spectra 22
2.7 Fabrication equipment 24
2.8 OSC measurements and characterization 27
Chapter 3 28
Improvement in the Efficiency of OSCs Based on a P3HT Donor and an ICBA Acceptor with Additional P3HT NWs 28
3.1 Introduction 28
3.2 Experimental section 30
3.3 Results and discussion 31
3.3.1 Morphological properties of ALs including P3HT NWs 31
3.3.2 Photovoltaic parameters of the four types of OSCs 33
3.3.3 EQE, LHE, and IQE spectra of the four types of OSCs 40
3.3.4 Cathode effects of P3HT:ICBA BHJ OSCs 46
3.4 Conclusions 48
Chapter 4 49
Effects of P3HT NWs on the ordering of donor/acceptor molecules in active layers 49
4.1 Introduction 49
4.2 Experimental section 52
4.3 Results and discussion 52
4.4 Conclusions 70
Chapter 5 71
Characterization of morphological properties of active layer by adding P3HT NWs 71
5.1 Introduction 71
5.2 Experiment and Simulation 73
5.2.1 Optical simulation 73
5.2.2 SCAPS simulation 74
5.3 Results and Discussion 76
5.4 Conclusion 88
Appendix A: Organic Ternary Devices with Additional P3HT NWs 89
Introduction 89
Experimental section 90
P3HT host- Device Fabrication 91
Si-PCPDTBT host- Device Fabrication 91
Results and Discussion 92
Conclusion 96
Appendix B: Summary of Organic Solar Cell Data 98
Appendix C: Cathode Effects of P3HT:ICBA BHJ OSCs 99
References 100
