Towards design of metal oxide free perovskite solar cell paradigm: Materials processing and enhanced device performance

•Flexible perovskite solar cell is fabricated with polypyrrole as efficient binding agent.•PC61BM layer is used as an electron transporting layer.•A high solar-to-electricity conversion efficiency of ∼6.38% is achieved.•Fabricated solar cell presents good charge transfer time and the recombination time.