All-solid solar cells with hybrid perovskite absorbers and graphene electron transport layers

This work reports the perovskite/titanium dioxide (TiO2)heterojunction solid state solar cells (SSSCs) with a hole transport material (HTM) and graphene electron transport layer. The effects of a nanostructure CH3NH3PbI3 perovskite thin film, the HTM, and graphene electron transport layer in SSSC structure were examined. The SSSCs prepared with the optimal parameter exhibited a short-circuit current density (JSC), open-circuit voltage (VOC), and power conversion efficiency (η) of 17.89 mA/cm2, 0.89 V, and 6.91%, respectively. Obvious improvements in power conversion efficiency of the SSSCs were observed by using the HTM and graphene electron transport layer. The HTM and graphene thin films provide a great hole and electron transfer channel for the photogenerated carriers to external circuit, respectively.