Surface-barrier photoconverters with graded-gap layers in the space-charge region

A novel possibility of controlling the parameters of p -Cu 1.8 S- n -II-VI surface-barrier structures by embedding a thin graded-gap layer into a photoconverter space-charge region (SCR) is implemented. The feature of quasi-electric fields built in the SCR, i.e., the fact that an increase in the drift field for minority carriers can be accompanied by a decrease in the potential barrier for majority carriers, is considered. The proper choice of the parameters of the Cd x Zn 1 − x S graded-gap layer embedded in the Cu 1.8 S-ZnS structure SCR made it possible to double the quantum efficiency in the ultraviolet spectral region. For Cu 1.8 S-CdS photoconverters with a (CdS) x (ZnSe) 1 − x intermediate layer, dark diode currents are decreased by three orders of magnitude while retaining a high quantum efficiency.