Graphene oxide modified PEDOT:PSS as an efficient hole transport layer for enhanced performance of hybrid silicon solar cells

Abstract

In recent years, PEDOT:PSS/n-Silicon (n-Si) based hybrid solar cells (HSCs) have drawn a significant attention as promising alternative to the conventional Si solar cell technology. However, poor electrical performance of the PEDOT:PSS limits the power conversion efficiency (PCE) of the device. Herein, tailoring the properties of the PEDOT:PSS via graphene oxide (GO) is investigated to use PEDOT:PSS-GO as an efficient hole transport layer (HTL) for the enhanced performance of the PEDOT:PSS/n-Si HSCs. A small amount of GO incorporation resulted in significantly improved structural, electrical, Si surface passivation properties of the PEDOT:PSS and hence the photovoltaic performance of the PEDOT:PSS-GO/n-Si HSCs. The study reveals that the oxygen functional groups on 2D-GO sheets interact with PEDOT:PSS and facilitates the improved electrical conductivity by >2 folds without affecting its optical properties. Further, the effective passivation of n-Si surface by the composite film has been found with enhanced minority carrier lifetime (∼1.7 folds). The PEDOT:PSS-GO/n-Si HSCs could achieve the highest PCE of 11.22% on device dimension of 1 cm2, which is absolute ∼4.14% higher with respect to that with the pristine PEDOT:PSS. The improved performance is attributed to the effective charge transport properties of the PEDOT:PSS-GO, interface passivation and thus efficient separation and collection of the photo-carriers for an optimum GO addition. The study establishes that PEDOT:PSS-GO composite could be used as an effective HTL for the efficient PEDOT:PSS/n-Si HSCs.