Differential analysis of TSC spectra in GaAs semi-insulating material

Abstract

The authors propose an analysis based on the second logarithmic derivative of the current in order to discriminate between the two typical recombination mechanisms (1st and 2nd order). It is shown that this method is feasible and leads to an unambiguous answer. The experimental case of Si:GaAs material is presented; six major peaks at 30, 60, 90, 140, 175 and 200K are analysed, all referring to first-order kinetics, thus indicating that the active recombination process is controlled by a high density of recombination centres. The exact determination of the recombination type allows a confident and precise determination of the typical parameters of the corresponding traps. It is found that the attempt-to-escape frequency is in the range 107 s-1 for the first group of traps (30, 60, 90K) whereas the others (140, 175, 200K) lie in the range 1011 s-1.