Mechanism of Two-Electron Exchange between Neutral and Ionized Centres of Tin in PbS1−xSex Solid Solutions

A Mössbauer study of the tin impurity in the PbS1−xSex solid solutions shows that tin forms two‐electron donor centres with a negative correlation energy for all 0 ⩽ x ⩽ 1. The position of the tin level relative to the valence band is determined. The two‐electron exchange between the Sn2+ and Sn4+ centres is explained by a transport of the electrons through the valence band. In addition, the 119Sn Mössbauer data give evidence that the germanium impurity forms two‐electron donor centres similar to the tin ones. [Russian Text Ignored].