Proceedings of International Conference on Perovskite and Organic Photovoltaics and Optoelectronics (IPEROP19)
Publication date: 23rd October 2018
The power conversion efficiency of perovskite solar cells has rapidly increased from initial 3.8% to 23.3% within just several years. However, all perovskite solar cells with the high performance consisted the organic group (i. e. methylammonium (MA+), formamidinium (FA+)), which restricts the perovskite solar cell development because of the poor stability of the organic cation under the thermal, moisture and ozone conditions. Inorganic cesium based perovskites have gained extensive interests because of the high thermal stability. The all inorganic perovskite solar cells can avoid the release or decomposition of organic cations. However, the α phase-instability of the inorganic perovskite film and poor performance of the solar cell devices were hindering the further progress. Herein, we found that the addition of GeI2 to CsPbI2Br perovskite stabilized the α phase of the perovskite at room temperature. Furthermore, VOC of up to 1.4 V (Voc loss: 0.5 eV) was obtained by the solvent engineering method which is a remarkable record in the field of inorganic perovskite solar cells.
The authors acknowledge JST Mirai Program for financial support.