Surface Modification of PEDOT:PSS for Enhanced Performance of Inverted Perovskite Solar Cells
Puan Lin, Wenfeng Zhang, Liuwen Tian, Lingbo Jia, Wen Fang, Gongtao Duan, Xiangqing Zhou, Shenghou Zhou, Fu Zhang, Yutong Jiang, Tao Chen, Fengguang Liu, Shangfeng Yang, Yuelong Huang
Abstract
Inverted perovskite solar cells (PSCs) with PEDOT:PSS as hole transporting layers exhibit tremendous prospects for flexible photovoltaic applications owing to their characteristics of low-temperature solution processability and favorable flexibility. Nevertheless, the energy level mismatch of PEDOT:PSS and perovskite layer results in a severe energy deficit. In addition, the acidity of PEDOT:PSS is detrimental to the stability of devices. To address these issues, we employ a glyceryl monostearate (GMS) interlayer to improve the work function and conductivity of PEDOT:PSS. Meanwhile, it can passivate the traps at the interface of PEDOT:PSS/perovskite. As a consequence, the champion power conversion efficiencies of photovoltaic devices based on MAPbI3 films increase from 14.82% to 17.29% due to the surface modification of PEDOT:PSS with GMS, which is mainly ascribed to the enhanced open-circuit voltage and short-circuit current density. Furthermore, the nonencapsulated MAPbI3 perovskite films and devices based on GMS-modified PEDOT:PSS show much better moisture stability and thermal stability than the counterparts without GMS modification.