Influence of Al content in the barrier on the optical properties of GaAs/AlxGa1-xAs (x=0.1-1) multiple-quantum-well structures.

摘要: GaAs/AlxGa1-xAs multiple-quantum-well structures with identical well thicknesses (almost-equal-to 119 angstrom) but different Al contents x in the barrier (x almost-equal-to 0. 1, 0.2, 0.45, and 1) were grown by molecular-beam epitaxy. We report characterization of a combination techniques. The x-ray-diffraction technique allows us to estimate content measure period structure good accuracy. Using photographs given high-resolution transmission electron microscopy on cleaved wedges, we investigate directly key parameters structures, such as regularity, layer thickness, x. photoluminescence measurements carried out detail from 4 K room temperature show excitonic character radiative recombination these up temperature. influence is investigated systematically. data confirm theoretical results calculated using finite heights. increase transition energies increasing due confinement exciton binding energies. A agreement parameter values obtained above techniques given.