Low-Temperature Processed and Carbon-Based ZnO/CH₃NH₃PbI₃/C Planar Heterojunction Perovskite Solar Cells

Carbon-based ZnO/CH₃NH₃PbI₃/C planar heterojunction perovskite solar cells (PHJ-PSCs) were prepared at low-temperature without using organic hole conductor and metal electrode. When measured via reverse bias scan, rigid and flexible PHJ-PSCs achieved power conversion efficiencies (PCEs) up to 8% and 4% on fluorine-doped tin oxide (FTO)/glass substrates and flexible polymer substrates, respectively. The flexible devices were capable of maintaining 80% of their initial PCEs after 1000 times of bending.