Energy spectrum and the nature of irradiation-induced defects in Pb1-xSnxSe alloys with inverse band structure

Abstract

This paper is devoted to the investigation of the effect of electron irradiation (T = 300 K, E = 6 MeV, Φ ≤ 7.1 × 1017 cm-2) on the galvanomagnetic properties of Pb1-xSnxSe (x = 0.20, 0.25) alloys. Experimental results were explained in the frame of the earlier proposed model of the energy spectrum for electron-irradiated Pb1-xSnxSe alloys, assuming that electron irradiation leads to appearance of a wide radiation defect band of the acceptor type in the forbidden band of the alloys and to redistribution of electrons between the conduction band and the radiation defect band. By comparing theoretical and experimental dependences of the electron concentration on the radiation flux the main model parameters of the defect formation process (the defect generation rate dNt/dΦ, the width σ and the energy position of the band Et) were determined in the alloys under investigation. It was shown that agreement between experimental and theoretical data took place only under the assumption that the introduction rate of radiation defects decreases with an increase in the radiation flux. In the present work we put forward the model according to which the major mechanism of the defect formation process in the alloys is the generation of complexes including the primary radiation defects and the intrinsic structure defects typical of initial crystals.