| 초록 |
Perovskite is expected to be the next generation material that can replace silicon in solar cells. According to NREL solar cell efficiency chart, the efficiency of perovskite solar cells is up to 23.7%. Perovskite solar cell has many advantages including low cost, convenient fabrication, tunable band gap compared with silicon solar cell. In perovskite solar cell structure, electron transport material(ETM) extracts electrons excited from perovskite layer (light absorption layer). Previous studies have shown that tin oxide(SnO2) has many advantages over titanium oxide(TiO2) and can be used instead of TiO2 in the ETM layer. SnO2 has faster electron mobility, and deeper conduction band compared with TiO2. The electrical properties of SnO2 facilitate faster charge transfer from perovskite to ETM layer. Unlike TiO2, SnO2 can reduce charge accumulation at interface between perovskite and ETM layer. The devices using SnO2 showed a certified efficiency close to 20%, almost free of hysteresis. In this study, we have found optimal conditions of formation of SnO2 ETM layer by adjusting experimental conditions including concentration of SnO2 particle solution, annealing temperature and time, and spin coating rate. Analysis of SnO2 layer from each experiment condition was conducted by SEM, XRD, AFM, XPS, etc. Also, LIV, QE, EL, LIT were used to analyze the characteristics of the device. |
