Capture kinetics at deep-level defects in lattice-mismatched GaAs-based heterostructures

Two deep-level traps associated with lattice-mismatch induced defects in GaAs/InGaAs heterostructures have been revealed by means of deep-level transient spectroscopy (DLTS). An electron trap, at E-c - 0.64 eV, has been attributed to electron states associated with threading dislocations in the ternary compound while a hole trap, at E-v + 0.67 eV, has been ascribed to misfit dislocations at the heterostructure interface. Detailed investigation of the dependence of DLTS-line amplitude and its shape on the filling time of the traps with charge carriers allowed us to specify the type of electronic states related to both traps. In terms of the model of electronic states associated with extended defects, which takes into account the rate at which the states reach their internal electron equilibrium, we relate the electron trap to "localized" states and the hole trap to "bandlike" ones. (C) 2001 Elsevier Science B.V. All rights reserved.