Optical Absorption Bands in Neutron Irradiated ZnSe and ZnS_0.5Se_0.5 Crystals

Abstract

In electron-irradiated ZnSe, the ESR signal due to the V-center which is a single hole trapped at a zinc vacancy has been observed by Watkins /l/, and the optical property of the center has been reported /2, 3/. In ZnS, the F+ center which is a single electron trapped at a negative ion vacancy is introduced by high-energy particle irradiation o r heat treatments and produces the 2.3 and 2.9 eV optical absorption bands /4 to 6/, but the F+ center in ZnSe has not yet been reported. On the other hand, the peaks of the emission bands analogous to Cu-B and Cu-G emissions in ZnS shift to lower energies a s the mole fraction x in ZnS1-xSex mixed crystals is increased /7/. Therefore it may be expected that the peak of the F+ center absorption band in ZnSl-,Sex mixed crystals shifts to lower energies with increasing x similarly to the emission peaks. In this note, the absorption spectra in neutron irradiated ZnSo. 5Se0. crystals were measured at 77 K. and ZnSeThe crystals used in this work were ZnSo. 5Se0. mixed crystals grown from the.melt in a high pressure vessel and ZnSe crystals grown by the sublimation method. The specimens were polished mechanically and their typical size was specimens, respectively 1) Koyama, Tottori 680, Japan.

The growth, structure and luminescence properties of ZnSe1-xSx materials

“…The change of the luminescence band maximum position is related to the shift of the fundamental absorption edge to longer wavelengths with the increase of the Se content [14,27]. Further decrease of the sulfur concentrations leads to the wurtzite-sphalerite transition for SSR-ZnSe 1-x S x samples and a significant shift of the luminescence band maximum to the long-wavelength region (λ max = 635 nm, Fig.…”