GROWTH AND CHARACTERIZATION OF GAAS DOPING SUPERLATTICES

GaAs doping superlattices with n- and p-doped layer thicknesses ranging from 200 angstrom to 600 angstrom have been grown by organometallic vapour phase epitaxy (OMVPE). Micrographs of the superlattice cross-section obtained using scanning electron microscopy (SEM) reveal highly uniform layers across the length of the sample. The extent of the carrier depletion across the p-n interfaces is determined from resistivity and Hall effect measurements on the n- and p-doped layers. The tunability of the effective bandgap of the doping superlattices is demonstrated in photoluminescence spectra recorded at different intensities of the optical excitation.