ZnTe-CdSe heterojunctions ii. photoelectric and luminescent properties

The photoelectric properties of ZnTe-CdSe heterojunctions illuminated by natural and laser light have been investigated. The crossing of the forward branch of the I-U curves in the dark and under illumination is a characteristic peculiarity for these heterojunctions. At 300 °K the maximum value of the open circuit voltage Uoc is 0.80 V. With laser light illumination Uoc reaches 1.4 V. The region of spectral sensitivity is limited by photons with energies equal to the forbidden gap of ZnTe and CdSe. The thickness of the CdSe layer has the main influence on the shape of the spectral distribution. The reverse voltage applied to the heterojunction leads to a long-wave shift of the peak caused by the generation of electron-hole pairs in ZnTe. Two types of samples with red and green luminescence have been obtained. The external quantum efficiency at 80 °K is equal to 1.2 to 1.6%.