Sb₂S₃-Sensitized Solar Cell by using TiO₂-Nanorod Arrays
- 주제(키워드) Solar cell
- 발행기관 고려대학교 대학원
- 지도교수 이석중
- 지도교수 석상일
- 발행년도 2013
- 학위수여년월 2013. 2
- 학위구분 석사
- 학과 일반대학원 화학과
- 원문페이지 66 p
- 실제URI http://www.dcollection.net/handler/korea/000000037934
- 본문언어 영어
- 제출원본 000045745728
초록/요약
Over the last few years inorganic-sensitized solar cells have received great attentions due to the intrinsically attractive properties of inorganic semiconductor sensitizers such as tunable band gap by size control, high extinction coefficients, large intrinsic dipole moment, multiple exciton generation, and good stability. Moreover, the production of inorganic semiconductor sensitizers is significantly cheaper compared to dye, since they are synthesized at low temperature and with solution-based approaches. At this point, they are excellent materials as light absorber for sensitized solar cells. In particular, Sb2S3 is very attractive materials for the application to solar cells because of its high absorption coefficient in visible region and suitable bandgap. However, efficient Sb2S3-sensitized photoelectrochemicalcells (Sb2S3-SPECs) have been rarely reported due to most liquid electrolytes have a corrosive effect on the unique structure of Sb2S3. The Sb2S3-SPECsexhibits stable performance only in cobalt electrolyte. Owing to the stronger absorption and bulkier dimension of Sb2S3 than dye attached on the TiO2 surface, cobalt electrolyte undergoes mass transport problem at the vicinity of Sb2S3 and cobalt electrolyte interface in pore space within mesoscopic TiO2 electrode. In addition, the backward recombination is caused by sluggish transport of cobalt electrolyte in the random nanoparticlulate TiO2 network producing increased recombination. In this thesis, to relieve the mass transport problem at vicinity of Sb2S3 and cobalt electrolyte and reduce the backward recombination in Sb2S3-SPECs, TiO2nanorodsphotoelectrode was used as a macroporous model electrode instead of conventional mesoporous TiO2. The TiO2nanorodsphotoelectrode could greatly relieve the mass transport problem of cobalt electrolyte in the vicinity of the Sb2S3 sensitizer in Sb2S3-SPECs. Therefore, the nonlinearity of the power conversion efficiency under illumination intensity was greatly relieved to 5.0% (0.1 sun), 4.7% (0.5 sun), and 3.7% (1 sun) in a TiO2-nanorod-based Sb2S3-SPECs, whereas the efficiency of a mesoscopic-TiO2-based Sb¬2S3-SPECs were significantly degraded to 5.3% (0.1 sun), 3.8% (0.5 sun), and 2.3% (1 sun). In addition, to further improve the device performance by reducing backward recombination at TiO2/Sb2S3/cobalt electrolyte, P3HT (Poly-3-hexylthiophene) interlayer was introduced in between Sb2S3 and cobalt electrolyte. The use of a P3HT coating layer enhanced significantly the solar cell efficiency to 4.2 % (1 sun) owing to the improved open circuit voltage by the reduced backward recombination.
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Abstract ⅰ
Contents ⅲ
List of Figures ⅴ
List of Tables ⅶ
1. Introduction 1
1.1 Dye sensitized solar cells (DSSCs) 4
1.1.1 History of DSSCs 4
1.1.2 Structure of DSSCs 5
1.1.3 Operating principle of DSSCs 6
1.2 Inorganic-sensitized solar cells (ISSCs) 8
1.2.1 Inorganic semiconductor sensitizers 8
1.2.2 Electrolyte 11
1.2.3 Photoelectrode 12
1.3 Electrical characterization 13
1.3.1 I-V curves 13
1.3.2 Quantum efficiency 21
1.4 Objectives of present work 23
2. Experimental section 24
2.1 Preparation of TiO2photoelectrode 24
2.2 Deposition of Sb2S3 sensitizers 25
2.3 Device fabrication 25
2.4 Characterization of device performance 26
3. Results and discussion 27
3.1 Design of photoelectrode : TiO2-nanorod arrays 27
3.2 Interface modification : P3HT interlayer 43
4. Conclusion 51
5. Reference 53
