Development of Chloromethyl Functionalized Poly (3,4-ethylenedioxythiophene) Derivative (PEDOT-MeCl:PSS) Hole Transport Layer for Perovskite Solar Cells

Abstract

Highly efficient planar perovskite solar cells with a chloromethyl functionalized poly(3,4-ethylenedioxythiophene) derivative (PEDOT-MeCl:PSS) as hole transport layer (HTL) were developed. A combination of characterization techniques was employed to investigate the effects of chloromethyl function group on the electron donation capability of PEDOT-MeCl:PSS, perovskite film quality and charge recombination kinetics in the solar cells. Our study shows that the presence of chloromethyl group at the PEDOT-MeCl surface gives the HTL a desirable energy level alignment with perovskite. The favorable interaction between the chlorine and perovskite provides a better crystal with less PbI2 comparing with PEDOT:PSS. As a result, better device performance with higher short-circuit current density (Jsc) and fill factor (FF) was gained, leading to better power conversion efficiency. Our study provides an insight to the development of new hole transport materials for high efficiency perovskite solar cells.