Determination of a relationship between spin-orbital and internal central splitting of acceptors into polarized luminescence for an orthogonal configuration

Abstract

The crystal of an extrinsic semiconductor typically comprises a large number of defects – vacancies, impurities, and complexes – whose symmetry, owing to internal distortions, differs from the symmetry of the initial material. Determination of the symmetry of complexes in the study of polarization luminescence [1, 2] requires knowledge of the symmetry of the initial state undistorted by the internal field. The type of representation of the initial state for complexes in cubic semiconductors is determined on the basis of polarization measurements for the orthogonal configuration of the photoluminescence associated with the impurity centers depending on a relationship between spin-orbital splitting Δso and internal splitting Δint of the initial state of the center. A crystal with the impurity having the initial fourfold degenerate ground state Г8 and the excited state Г6 (Δso >> Δint) for every possible equivalent equiprobable directions of internal distortion axes is considered. In addition, centers with the initial t2-type state (neglecting spin-orbital splitting for Δso << Δint) and the excited s-type state are also considered. The wave functions of deep centers were found within the framework of the effective Hamiltonian method. Under the action of distorting fields, the Hamiltonian of a hole in the initial state Г8 assumes the form