Intracenter excitation of the 630 nm band in ZnSe crystals

Abstract Spectral studies of a known luminescence band with a maximum wavelength of 630 nm have been carried out on undoped ZnSe crystals. The spectral position of the intracenter excitation band is determined. It is identified using the photoconductivity spectra and the luminescence excitation spectra of the 630 nm band that the transitions from the ground state to an excited state of that center. Result in an absorption band of 520 nm (2.38 eV). An intracenter luminosity spectrum is obtained from the excitation at that absorption band, with the value of the Stokes shift being ΔEC = 0.48 eV. A comparison of the luminescence spectrum at an intracenter excitation against the same at a zone-zone UV excitation and an X-ray excitation shows that they differ noticeably from each other. A half-width of the luminescence band is smallest at the intracenter excitation and the position of its spectral maximum is the same for different samples. This confirms that the 630 nm band is non-elementary for luminescence quenching of ZnSe crystals with above-bandgap energies.