Tetra-alkyl-substituted copper (II) phthalocyanines as dopant-free hole-transport layers for planar perovskite solar cells with enhanced open circuit voltage and stability
Tetral-alkyl substituted CuPc were employed as hole transporting material for perovskite solar cell. Tetra-alkyl substitution increased the π-π interactions, carrier mobility and hydrophobicity. CuMePc exhibited highest PCE of 11.9%. CuEtPc exhibited best long term stability.