Growth of undoped, high purity, high resistivity ZnSe layers by molecular beam epitaxy

Abstract

The growth of undoped, high purity ZnSe layers by molecular beam epitaxy with extremely high purity Se source materials refined by sublimation is described. The resistivity of these layers is greater than 104 Ω cm. In low-temperature photoluminescence spectra, only free-exciton emission line becomes dominant and all the bound exciton emission lines are extinguished, which is characteristic of very high purity ZnSe. Detailed behavior of electrical and optical properties of normally undoped layers is remarkably dependent on the purification cycles of Se materials used as source materials. The results indicate that the high resistivity of undoped, high purity ZnSe layers is due to a reduction of residual donor impurities.