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 (SiO 2 ) nanoparticles are added into the CsPbI 2 Br 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 CsPbI 2 Br layers, the added SiO 2 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 SiO 2 nanoparticles into CsPbI 2 Br, ∼18.39% enhancement of the power conversion efficiency (PCE), that is, from 12.94 to 15.32%, for a simple demonstration configuration of ITO/SnO 2 /CsPbI 2 Br/P3HT/Ag, as compared with the control device without adding the SiO 2 nanoparticles, is achieved. In addition, the SiO 2 nanoparticle-added CsPbI 2 Br 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.