FEATURES OF PHOTOLUMINESCENCE OF GAAS-TYPE SEMICONDUCTORS ASSOCIATED WITH SHALLOW ACCEPTORS IN A MAGNETIC FIELD

Abstract

By the method of Picus and Beer invariants, general expressions were obtained for the full intensity I and the degree of circular polarization of the Pcirc photoluminescence of GaAs-type semi-conductors in a longitudinal magnetic field H with the participation of small acceptor levels. Special cases are analyzed depending on the value and direction of the magnetic field strength, as well as on the sign of the Zeeman constants of the g-factor of the acceptor g1, g2 and the electron of the ge conduction band. In the case of a strong magnetic field H // [100], [111], [110] the numerical calculation of the angular dependence of the values I and Pcirc is performed for some critical values of the g2/g1 ratio, at which Pcirc reveals a sharp anisotropy in the range from –100 to +100 %, and the intensity of the crystal radiation along the magnetic field, it tends to a minimum value. It is shown that with a weak magnetic field, there is an angular dependence for the total intensity, but it does not manifest itself in the degree of polarization of the radiation. In the case of a strong magnetic field, the character of the angular dependencies I(), Pcirc() is determined by the sign of the ratio of the g-factors ge/g1 and g2/g1. An experimental study of the dependences of the intensity and degree of polarization of luminescence in a magnetic field caused by the optical transition of free electrons to the level of a small acceptor on the orientation of the vector H in the crystal allows us to find the values of the constants g1 and g2, as well as to establish some characteristic features of radiation.