A transient capacitance-voltage method for characterizing DX centres

Abstract

A transient capacitance-voltage (TCV) method is proposed for measuring the net donor concentration, the free electron concentration and the space charge distribution of Schottky diodes prepared on Si-doped AlGaAs. The utility of this method is demonstrated by determining the binding energy of the DX centre from the temperature-dependent free electron concentration. Comparisons of the space charge distribution between theory and experiment are performed for the positive-U and negative-U model of the DX centres. The results obtained or the negative-U model are consistent with recent observations of multi-DX levels.