DLTS study of Be-doped p-type AlGaAs/GaAs MBE layers

Deep-level transient spectroscopy method was applied to study deep hole traps in p-type Al0.5Ga0.5As grown on GaAs semi-insulating substrate by MBE. Five hole traps labelled by us as H0 to H4 were found. For the traps H1, H3 and H4 thermal activation energies obtained from Arrhenius plots were equal to: E-H1 = 0.15 eV, E-H3 = 0 4 eV, and E-H4 = 0.46 eV. Hole emission from the trap H2 was electric field dependent with the thermal activation energy extrapolated to zero-field equal to 0.37 eV. Capture cross-sections for the traps H1 and H4 were thermally activated with energetic barriers 0.04 eV (for H1) and 0.18 eV (for H4).