Self-Activated Luminescence In ZnS–ZnSe System From Positions Of The Band Anticrossing Model

Abstract:

Spectra cathodoluminescence CVD-samples of the ZnS-ZnSe system, grown in the entire range of compositions are investigated. Reorganization of spectrum at dissolution of oxygen in the lattice under influence of high pressures and temperatures treatment is confirmed. Dependence of the self-activated luminescence on composition sulfoselenides is revealed. The explanation to these features is given on the basis of calculations of intrinsic point defects (IPD) equilibrium, which influence in the position of the Fermi level at a deviation from stoichiometry ZnSe and ZnS. Areas in which bands self-activated luminescence SA and SAL ZnS-ZnSe system can be observed depending on IPD type and concentration of oxygen in the lattice are appreciated. Interpretation of spectra is given for the first time on basis of the band anticrossing model initiated isoelectronic impurity of oxygen. Results can be used for the semiquantitative control of compound for similar crystals А2В6 over the content of dissolved oxygen and deviation from the stoichiometry Properties of А2В6 alloys, widely used in optoelectronics, essentially depend on the presence of a background impurity of oxygen. Currently, there is sufficient experimental material proving that selfactivated luminescence is connected to intrinsic point defects (IPD) complexes with oxygen. These complexes can be divided into different kinds [1] determined by type and charge within the homogeneity area. In [1] on the example ZnS, ZnSe and CdS the possibility of appearance of 3 types of self-activated bands, designated as: I (SA)–at excess of metal, II (SAL)–in area stoichiometry and III–at significant excess of …

Año de publicación:

2006

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