Preparation and Properties of Al(x) Ga(1-x) Sb for Application to Luminescent Devices.

摘要

The ternary phase diagram of the Al-Ga-Sb system was established in the Ga-rich region. Al(x)Ga(1-x)Sb layers with Al concentration x varying from 0.0 to 0.92 were grown on (111) oriented GaSb substrates in a Ga-rich melt using a vertical dipping liquid phase epitaxy system. The dependence of bandgap energy on Al concentration x in the mixed crystal was measured in undoped layers using optical absorption wavelength modulated absorption, photoluminescence and electron beam microprobe techniques at 77 and 300K. The infrared lattice vibration spectra of the Al(x)Ga(1-x)Sb system were studied in the reststrahlen region. Room temperature reflectance spectra were measured in a double beam mode at near normal incidence in the spectral range from 180 to 520/cm. The composition dispersion in the TO phonon branches was studied by using the random element isodisplacement (REI) model. The six-parameter REI model was found to be the best approach in describing the Al(x)Ga(1-x)Sb system.