Interband photoconduction edge in zinc sulphide thin films

Abstract

Photovoltaic phenomena similar to phototransition effects are induced in ZnS sputtered films by light of energy beneath the band-gap (not more than 0.22 eV). It is advanced that hot electron may escape from the photoionized coulombic centre and moves to some level within shallow traps distribution. Thickness dependent phenomena confirm the existence of a critical thickness in which the density of coulombic centres is higher.