Interband critical-point line shapes in confined semiconductor structures with arbitrary dimensionality: Inhomogeneous broadening

The interband optical transitions near van Hove critical points in semiconductor structures with restricted geometry are studied in the framework of fractional dimensionality in the case of inhomogeneous broadening. The spectral line shapes were derived based on the w function, which is the envelope of the individual homogeneous packets. Similar to the case of homogeneous broadening, the dimensionality, band gaps, and linewidths can be straightforwardly determined by use of fractional differentiation, which converts the line shapes to symmetric profiles. The results show that crystal potential fluctuation plays an important role in the interband optical transitions, and the total linewidth should be accounted for by both phonon processes and crystal strain. (C) 1997 Optical Society of America.