Inorganic Perovskite Solar Cells with High Voltage and Excellent Thermal and Environmental Stability

• Published in: ACS applied energy materials 2022-05, Vol.5 (5), p.6265-6273
• Main Authors: Zhu, Junhao, Kottokkaran, Ranjith, Sharikadze, Saba, Gaonkar, Harshavardhan, Poly, Laila-Parvin, Akopian, Arkadi, Dalal, Vikram L.
• Format: Article
• Language: English
• ISSN: 2574-0962; 2574-0962
• DOI: 10.1021/acsaem.2c00624

The lack of high temperature and atmospheric stability of perovskite solar cells has been one of the primary obstacles hindering the commercialization of this emerging photovoltaic material. This work presents an all-inorganic CsPbBr3 perovskite solar cell with excellent stability under both thermal and environmental stress. The perovskite layer was fabricated with a well-controlled layer-by-layer vapor deposition technique and subsequently annealed in a two-stage process. The solar cells have an overall device architecture of FTO/c-TiO2/CsPbBr3/buffer layer/P3HT/Au. A large band gap PbBr2 buffer layer is inserted between the intrinsic layer and the hole transport layer. This layer inhibits the recombination of electrons at the p–i interface, improving the performance of the solar cell. The open-circuit voltage exhibited by these devices is 1.64 V, the highest open-circuit voltage (V oc) ever reported for this perovskite material. Additionally, the devices yielded a photo-conversion efficiency of 7.9%. The isolated perovskite layer showed no degradation when annealed at temperatures up to 300 °C for 24 h. The solar cells withstood exposure to an environment of ambient air at 20 °C for 500 h without any loss in efficiency. Even a high-temperature (200 °C) exposure in air did not result in changes in the efficiency. The excellent environmental tolerance and high V oc indicate the potential for this perovskite to be used in a 4-terminal tandem solar cell arrangement with Si.