Optical Analyses of Si and GaAs Semiconductors by Fractional-Derivative-Spectrum Methods

Optical spectra analysis provides a wealth of information on physical properties of various semiconductor materials. Fractional derivative spectrum technique is especially interesting when the limitations of the standard treatment occur. In this paper we present the fractional derivative spectrum method for analysis of the optical spectra for both Si and GaAs. The significant changes in critical point parameters in each treated Si and GaAs samples in comparison to that before treatment have been observed. Our investigation illustrates that fractional derivative spectrum is a very good technique to extract basic information on relevant physical quantities from the observed optical spectra, and it has the advantages of flexibility, directness, and sensitivity, which give possibility to obtain the Van Hove singularities (critical point parameters) efficiently with one consent.