Nonfullerene Organic Solar Cells with 18.17% Efficiency Obtained Using a V<sub>2</sub>C/PEDOT:PSS Composite Hole-Transport Layer
Qun Gu, Jie Wang, Ruixiang Peng, Wei Song, Lin Xie, Rong Zhou, Ziyi Ge
Abstract
More efficient promotion of charge collection and transport is an essential factor to achieve high efficiency of the devices; however, the matching of energy level between the PEDOT:PSS hole-transport layer (HTL) and indium tin oxide (ITO) is not perfect, which limits the efficiency of exciton utilization. Herein, the composite HTL of V 2 C/PEDOT:PSS is formed using two-dimensional (2D) conducting material V 2 C and PEDOT:PSS, which shows a lower work function (WF) and higher conductivity than the pure PEDOT:PSS films and shows advantages to improve the Ohmic contact between the active layer and electrode. The efficiency of the devices prepared with the V 2 C (0.075 mg/mL)/PEDOT:PSS composite HTL based on the nonfullerene PM6:BTP-eC9 system reaches 18.17%. The enhancement in performance can be ascribed to the interaction between the functional groups of V 2 C and PEDOT:PSS, as well as the increase in the overall hole-transport layer conductivity. The method proposed in this study to prepare this V 2 C/PEDOT:PSS composite HTL improves the efficiency of organic solar cells.