Efficient and stable planar perovskite solar cells with a PEDOT:PSS/SrGO hole interfacial layer

An efficient planar perovskite solar cell (PSC) was fabricated with a bi-layer consisting of the poly (3,4-ethylenedioxythiophne):poly (styrene sulfonate) (PEDOT:PSS) and sulfonic acid functionalized graphene oxide (SrGO) as a hole interfacial layer. The low temperature and solution processed PEDOT:PSS/SrGO interlayer produced better power conversion efficiency (PCE) of 16.01% than other single layers. Comprehensive investigations reveal that the increased PCE is mostly due to the decreased recombination and the increased built in potential for better charge transport and extraction. In addition, the device with PEDOT:PSS/SrGO showed excellent long-term stability in ambient air conditions. Consequently, these results support that the introduction of graphene materials into interlayers can be a promising approach for high performance and cost-efficient solar devices.