Enhanced performance of polymer solar cells with PSSA-g-PANI/Graphene oxide composite as hole transport layer

Abstract

A new class of hole transport layer (HTL), which is composed of poly(styrene sulfonic acid) grafted with polyaniline (PSSA-g-PANI) and graphene oxide (GO), was prepared by adding GO into PSSA-g-PANI aqueous solution. The PSSA-g-PANI/GO composites exhibit high optical transparency and high electrical conductivity. When the composite with 2.5 wt% GO loading was used as HTL material for the device based on poly(3-hexylthiophene)/PC61BM blend, the device exhibits an enhanced power conversion efficiency (PCE) of 4.23%, which is 23% higher than the PCE of device with the conventional HTL material, PEDOT:PSS (3.44%). This enhancement of PCE arises mainly from an increase of the short circuit current density due to higher optical transparency and higher electrical conductivity of PSSA-g-PANI/GO composite. When the PSSA-g-PANI/GO composite is applied as HTL to a low bandgap polymer-based solar cell, PTB7:PC71BM blend, the PCE is also enhanced as compared to the device with PEDOT:PSS, providing us with the possibility to use PSSA-g-PANI/GO as a hole transport layer for various polymer-based solar cells to enhance the photovoltaic performance. (C) 2014 Elsevier B.V. All rights reserved.