OPTICAL-ABSORPTION AND EXCITON LINEWIDTHS OF ZN(1-X)CD(X)SE QUANTUM-WELLS

Comparison of experimentally determined optical spectra of Zn1-xCdxSe/ZnSe quantum wells with theoretical results for fundamental optical absorption and exciton linewidths is used to determine valence-band offset and properties of exciton features as a function of well width and temperature. The heavy-hole valence-band offset is found to be approximately 90 meV for x = 0.23. The exciton linewidths are analyzed in terms of Gaussian inhomogeneous broadening attributable to expected sample inhomogeneities involving well widths and alloy concentrations and homogeneous broadening associated with exciton-optical-phonon interactions. The linewidths are found to be smaller and larger than the bulk value for narrow (30 angstrom) and wide (200 angstrom) widths, respectively, in agreement with experimental results.