A solution-processable copper(II) phthalocyanine derivative as a dopant-free hole-transporting material for efficient and stable carbon counter electrode-based perovskite solar cells

A solution-processable copper(II) phthalocyanine derivative coded as CuPc-TIPS has been synthesized and adopted as a hole-transporting material (HTM) in perovskite solar cells (PSCs), in combination with a mixed-ion perovskite absorber and a low-cost carbon cathode. Optimised PSC devices based on pristine CuPc-TIPS without any additives or dopants show a decent power conversion efficiency of 14.0% (measured at 100 mW cm(-2) illumination, AM 1.5G), together with a good long-termstability under ambient conditions. The present finding highlights the potential of solution-processed copper phthalocyanine derivative-based HTMs for the development of efficient and stable PSCs in the future.