Enhancing the performance of organic solar cells by using PDINN-doped PEDOT:PSS as the hole transport layer

Abstract

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS), an aqueous-based material, is widely used in the fabrication of hole transport layers (HTLs) of organic solar cells (OSCs). However, it still suffers from the disadvantage of low electrical conductivity, which hampers charge collection and causes stability issues in OSCs. Here, a perylene diimide derivative, PDINN, which is commonly used as a cathode interlayer in OSCs, was introduced into PEDOT:PSS to improve its electrical conductivity. PEDOT:PSS-PDINN-based OSCs exhibit an elevated power conversion efficiency (PCE) and long-term stability compared to PEDOT:PSS-based OSCs. A PCE of 17.53% has been achieved for bulk-heterojunction OSCs using PM6:Y6 as the active layer, which is among the highest PCE values reported for devices based on the PM6:Y6 active layer. In addition, the unencapsulated device maintains 95% of its pristine PCE after 2016 hours of storage in a glove box under a nitrogen atmosphere. Moreover, D18:LB-BO BHJ devices achieve a dramatic PCE of 18.32%, higher than that of the control device (17.66%), indicating the generality of this HTL in non-fullerene-based high-efficiency OSCs.