Measurement of exciton diffusion lengths of phthalocyanine derivatives based on interlayer excitation transfer

► Delta-function-like exciton distribution created by interlayer excitation transfer ► Simple analysis of thickness dependence of photocurrent enabled by this distribution ► Exciton diffusion length (LD) obtained for several phthalocyanines (Pcs) ► LDs of ~ 5 nm shown by copper and metal-free planar Pcs ► Longer LD of 18.5 ± 4.8 nm shown by pyramidal-shaped tin Pc