Spectroscopic ellipsometry studies of excitonic features and optical functions of Al sub(x)Ga sub(1-x)As/GaAs multiple quantum well structures

Spectroscopic ellipsometry has been shown to provide a rapid, room-temperature, non-destructive assessment technique for quantum well structures ranging from a single well to 100-period structures. Good agreement for the first three transition energies was obtained for a series of well widths, using a 65% conduction band offset. Modelling the spectra by using individual layer bulk di-electric functions and by effective layer approximations has been compared. The optical functions of a single 50 angstrom well structure have been determined.