Graphene in Large Area Hole Conductor Free Perovskite Solar Cells

Abstract

Carbon-based hole conductor free fully printable perovskite solar cells (PSCs) has caught quite an attention in the perovskite field since the introduction of the novel architecture in 2014. Thanks to the incredibly high stability of this device architecture compared to the standard gold based perovskite solar cells. TiO2 has been typically used as an electron transport layer (ETL) in this type of architecture. Recently, graphene-based ETLs has shown to be a good substitute to pristine TiO2 to achieve higher conductivity and higher carrier injection leading to better performance. Here, we show the composite of graphene and TiO2 as a promising ETL for more efficient and stable perovskite solar cells. The composite, when used as an ETL, shows improvement in current density and fill factor. Moreover, we also observe a drastic improvement in stability of these PSCs compared to the reference cells.