Excellent electron transport via inserted a special electron-withdrawing material on SnO2 surface for high efficient perovskite solar cells

Abstract

Cyano (–CN) is an electron withdrawing group which can combine with the lead defect of the anti-bond to stabilize the structure of the perovskite, and simultaneously strengthens the transmission of electrons. Hexacyanobenzene (Ph(CN)6) has six –CN groups, which enhances electron-withdrawing and passivation of perovskite defects. The power conversion efficiency (PCE) of the optimal device reached 20.791%, the current density (Jsc) was 22.879 mA/cm2 after embedding Ph(CN)6 on SnO2 surface.