Photoconduction in Copper Oxinate

Abstract

The photocurrent transient in copper oxinate was measured. Copper oxinate has two photoconductive regions: one of them corresponds to the lowest singlet optical absorption band and the other lies in the low wavenumber side of the same band. Under irradiation, the photocurrent in both wavenumber regions abruptly rises to a maximum, and then it decreases gradually and settles to the steady state. In mixed single crystal (69 mol % palladium oxinate—31 mol % copper oxinate), such decreasing of photocurrent is also observed in photocurrent due to copper oxinate, while it is not observed in photocurrent due to palladium oxinate. The decreasing of photocurrent is not caused by the presence of carriers but caused by the excitation of specific molecule (copper oxinate) in the crystal, and the photoconduction in low wavenumber region is attributed to the excitation of copper oxinate.