S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Material Science and Engineering (재료공학부) Theses (Master's Degree_재료공학부)
Halide perovskite solar cells prepared from electrodeposited precursor films
전기증착된 전구체 막으로부터 형성된 할라이드 페로브스카이트 태양전지
- 공과대학 재료공학부
- Issue Date
- 서울대학교 대학원
- 학위논문 (석사)-- 서울대학교 대학원 : 공과대학 재료공학부, 2018. 8. 김진영.
- Hybrid organic-inorganic perovskite thin films have become promising materials for next-generation photovoltaic devices such as solar cells, photodetectors, and the light-emitting diode. As for the solar cell, the perovskite solar cells (PSCs) has gained much interest due to low-cost, simple solution-process, and high power conversion efficiency (PCE). Recently, single-junction perovskite solar cells PCE had reached higher than 22 % using solution spin-coating process. Also, the relatively large bandgap of perovskite materials enables the fabrication of tandem solar cells with Si thin film solar cells which have small band gaps. However, Si cell usually has random pyramid textures for efficient light harvesting, which makes it hard to form compact and crystalline perovskite layer through conventional solution spin-coating technique. To address these issues, electrochemical deposition is used, which is simple and applicable to large substrate area and rough surface. In this thesis, uniform and compact CH3NH3PbI3 (hereafter MAPbI3) film was formed through chronoamperometric electrodeposition method followed by sequential chemical vapor conversions.
First, PbO2 films were electrodeposited on ITO substrate with thin NiOx layer. PbO2 layers thickness and grain size were controlled through changing deposition potential and time, which greatly affected the converted MAPbI3 thickness and surface morphology. Then, the PbO2 film was reduced to PbO film with hydrogen gas and sequentially converted to MAPbI3 with CH3NH3I (hereafter MAI) vapor. Both PbO and MAPbI3 nucleus grow under the diffusion-controlled mechanism.
This thesis suggests a possible solution to address perovskite solar cell issues such as large-area cell and application to the tandem solar cell. Electrodeposition and vapor conversion are proved to be simple and scalable methods and thus are expected to address to low-cost and large scalable production of PSCs.