Photovoltage Properties of CdSe-Ge Isotype Heterojunctions

The fabrication and photo-response data are described for n-n CdSe-Ge heterojunctionswhich were made by vacuum evaporation of CdSe. A model is given which theoretically explains part of the shape of the spectral dependence of the photovoltage produced at zero bias. In forward bias, with the CdSe positive, the sign of the photovoltage changes and this points to a double-depleted band diagram dominated by acceptor-type interface states. Two applications of the photocharacteristies are briefly outlined: one describes a possible null-detecting frequency meter and the other a null-detecting optical pyrometer.