Get access

Charge separation in organic semiconductor blends studied by electrical in situ characterization during film growth



The influence of the substrate temperature during film growth as well as annealing of films subsequent to preparation was studied by in situ measurements of conduction and photoconduction of molecular blends of phthalocyaninatocopper (PcCu) and buckminster-fullerene (C60). The findings are discussed in context of structural and morphological changes observed in scanning electron microscopy (SEM) and UV/Vis transmission measurements. Deposition of bulk heterojunctions (BHJs) at elevated substrate temperature featured improved percolation pathways leading to increased conductivity, photoconductivity, and exciton dissociation yield. At low concentrations of PcCu in C60 electron trapping by light-induced hole states in PcCu was observed.