N-functionalized graphene derivatives as hole transport layers for stable perovskite solar cell

In this work, three Nitrogen-functionalized graphene (NGs): amino-graphene (G-NH2), graphene-ethanolamine (G-EA), and graphene ethylenediamine (G-EDA) have been synthesized and tested as hole transport layers (HTL) for perovskite solar cells (PSCs) applications. Among the evaluated graphene-based derivatives, the PSCs fabricated with graphene-ethylenediamine (G-EDA) showed best power conversion efficiency of 12.9%. The enhanced PCE of G-EDA based PSCs as compared to other NGs are attributed to the uniform coverage, faster hole transportation, and a template for larger perovskite crystal growth. Moreover, the PCE of the PSCs fabricated with G-EA and G-EDA based HTLs remain stable even after 200 h of light-soaking.