Performance enhancement of all-inorganic carbon-based CsPbI2Br solar cells by using silane modification

The CsPbI 2 Br perovskite solar cells (PSCs) based on the carbon electrodes are considered as promising photovoltaic devices with low cost and excellent thermal stability. Although the power conversion efficiency (PCE) has made remarkable progress, recombination originating from surface defect states of perovskite is still serious. In this work, CsPbI 2 Br layer was treated by n-propyltrimethoxysilane (NPTMS) before covering carbon electrode, and effects of NPTMS modification on the microstructure and optoelectronic properties of CsPbI 2 Br films were systematically studied. We found that NPTMS effectively passivated the CsPbI 2 Br surface states and inhibited nonradiative recombination via the strong coordination of O atom with the surface atoms. As a result, the power conversion efficiency of the CsPbI 2 Br perovskite solar cell increased from 8.78 to 10.22%.