Homogeneity range and nonstoichiometric defects in IV–VI narrow-gap semiconductors

Abstract

Enthalpies of Schottky defect formation in narrow-gap Pb 1− x Sn x Te ( x = 0, 0.2) and Pb 0.93Sn 0.07Se solid solutions have been determined. Low values of the enthalpies ( H M v = 0.45 eV, H Ch v = 0.70 eV) define high values of vacancy concentrations at T = 800 K in the metallic and chalcogen sublattice ( N M = 5 × 10 19 cm −3, N Ch = 10 18 cm −3), which practically prevents a reproducible manufacturing of layers of these semiconductors with free carrier concentrations less than 3 × 10 16 cm ⋊3.