Reducing the Voc Loss of Hole Transport Layer-Free Carbon-Based Perovskite Solar Cells via Dual Interfacial Passivation

Abstract

Li2CO3 is used to modify conformal SnO2 as electron transport layer for hole transport layer-free carbon-based perovskite solar cells (C-PSCs). CO32− can induce MA release from the perovskite layer, resulting in PbI2 at the grain boundary of top interface of perovskite film which can passivate the grain boundary and the top surface defects. The Li2CO3-modified C-PSC exhibits a high power conversion efficiency (PCE) of 19.1%, with a Voc of 1.142 V. A record-high PCE of 33.2% is obtained under weak light-emitting diode illumination (2000 lx, 3000 K).