Photo-Deep-Level Fourier Spectroscopy in Semi-Insulating Bulk Materials

A new technique called photo-deep-level Fourier spectroscopy (photo-DLFS) for evaluating deep levels in semi-in-sulating materials is proposed. It is presented with a frequency space analysis that makes it possible to analyze the deep-level parameters, without correction for the complicated temperature dependence in the current-transient equation, using numerical calculation of the Fourier coefficients taken from the Fourier transforms of the transient current values. Seven deep levels were detected in semi-insulating undoped LEC GaAs crystals using this method. Also, a comparison is made with the photo-DLTS method.