Study of Non-Linear Extrinsic Luminescence in GaAs III. Sublinear Emission Due to Auger Transitions in Radiative Centres

Abstract

The excitation intensity dependence of the 0.94 and 1.0 eV extrinsic emission in n-type GaAs crystals (n0 ≈ 1017 cm−3) is studied at L ⪅ 1018 quanta/cm2 s and T = 77 K. Linear and sublinear 0.94 and 1.0 eV extrinsic emission is observed depending on the strength of the non-radiative electronic transitions in the radiative centres studied. The main features of the non-linear extrinsic emission (the sublinear emission increase with excitation intensity, a decrease in the internal quantum efficiency of the extrinsic emission and in the luminescence decay time as exciting power is increased) are satisfactorily explained by a model which takes into account an increase in the rate of non-radiative electronic transitions in 0.94 and 1.0 eV radiative centres as the exciting light considerably changes the hole occupancy of defects associated with the centres studied. [Russian Text Ignored.]