Enhancing the Photovoltaic Performance of CsPbI2Br Solar Cells by Adding SiO2 Nanoparticles into the Photoactive Layer

Herein, we report a facile additive-engineering scheme, in which silicon dioxide (SiO2) nanoparticles are added into the CsPbI2Br photoactive layer, to improve the comprehensive performance of the inorganic perovskite solar cells. A systematic study indicates that besides the improved crystallization quality, reduced trap density, and enhanced resistance to moisture and silver (Ag) diffusion for the CsPbI2Br layers, the added SiO2 nanoparticles also lead to the enhanced light absorption and thus to the increased short-circuit current density for the device. Thanks to these positive effects owing to the adding of SiO2 nanoparticles into CsPbI2Br, similar to 18.39% enhancement of the power conversion efficiency (PCE), that is, from 12.94 to 15.32%, for a simple demonstration configuration of ITO/SnO2/CsPbI2Br/P3HT/Ag, as compared with the control device without adding the SiO2 nanoparticles, is achieved. In addition, the SiO2 nanoparticle-added CsPbI2Br device exhibits improved operation stability, that is, >80% retention of the initial PCE after aging in air with a relative humidity of 20-30% for 160 h, as compared to the control device.