Determination Of Trap Parameters From Photocurrent Decay Measurements: Metal-Free Phthalocyanine Films

Abstract

The energy distribution of traps in gap samples of thin vacuum-evaporated metal- free phthalocyanine (H₂Pc) films was determined from measurements of photocurrent decays performed at several temperatures, in a nitrogen atmosphere. The parameters of the traps were determined using a straightforward method of the analysis of a first-order process, with distributed parameters. It was found that the photocurrents are controlled by a narrow distribution of shallow traps peaking at about 0.2 eV, with a distribution width of about 0.015 eV and a very low effective attempt-to-escape factor.