Zinc sulphide linear photodetector

Interband phototransitions and photoionization of coulombic centres allow linear detection of light intensity in Al/ZnS/Au photocells. The opposite spectral variations of photoconduction and apparent internal electric field lead to a maximum of spectral sensitivity of about 15A mW^–1 in the u.v. region for 500 Å sulphide thickness. Adequate simplified band models are proposed.