Gap Variation in Semiconductor Alloys and the Coherent-Potential Approximation

The well-known results of the coherent-potential-approximation (CPA) alloy theory are useful for understanding the energy-gap variation in semiconductor alloys. A CPA theory of the valence bands in III-V compounds demonstrates that alloy disorder can contribute significantly to the band-gap bowing parameter, while causing very little broadening of the E₀ spectra. We conclude that the CPA should replace the earlier theories for studying the electronic structure in semiconductor alloys.