The Spectra of X-ray and Photoluminescence of High-Resistance Crystals of ZnSe

Abstract

The luminescence spectra of high-resistance ZnSe crystals consist of two main bands with maxima at 630 nm (1.92 eV) and 970 nm (1.28 eV). The planned comparison has been carried out between the spectra of X-ray luminescence and photoluminescence of ZnSe among themselves in the spectral region from 400 to 1200 nm at different excitation intensities and different temperatures (8, 85, 295, and 420 K). It is found that the forms of luminescence bands do not depend on the excitation intensities. The band form with a maximum at 970 nm also does not depend on the excitation type, and the band at 630 nm differs slightly under the X-ray and UV excitations. The temperature dependences of the spectral positions of bands’ maxima and their half-widths are analyzed. A conclusion is drawn that the 970-nm emission band is elementary. A short-wavelength shift of the spectral maximum of the 630-nm band with increasing the temperature makes it possible to conclude that this luminescence band is non-elementary. This correlates with the previously discovered feature of this band related to the realization of two recombination mechanisms (electron and hole) at this luminescent center.