Characteristic features of the temperature dependence of the photoluminescence polarization of {Ga vacancy}-Sn-Ga(Si-Ga) complexes in GaAs produced as a result of resonant polarized excitation

The excitation and induced polarization spectra of the photoluminescence ba nd with the maximum near a photon energy of 1.18 eV in Sn- or Si-doped n-Ga As with an electron density similar to 10(18) cm(-3) are measured at variou s temperatures. It is shown that the temperature dependence of the induced polarization of this photoluminescence due to VGaSnGa or VGaSiGa complexes in the temperature range 77-230 K is close to the corresponding dependence for VGaTeAs complexes. In addition, a slight decrease in the induced polari zation as the temperature is increased, not observed for VGaTeAs complexes, is observed in the range 77-125 K for the investigated complexes. It is hy pothesized that the difference is attributable to the existence of excited configurations in the absorbing and emitting states of the VGaSnGa and VGaS iGa complexes, where the populations of these configurations in the absorbi ng state increase with the temperature. The difference between the total en ergies of the excited and ground configurations of the absorbing state is 1 0-20 meV for VGaSnGa complexes and 15-30 meV for VGaSiGa complexes. (C) 199 9 American Institute of Physics. [S1063-7826(99)01001-7].