OPTICAL AND ELECTRICAL CHARACTERIZATION OF AN ALGAAS GAAS HETEROSTRUCTURE/

Photoreflectance (PR) spectroscopy and Hall-effect measurements have b een used for the analysis of a molecular beam epitaxially grown AlGaAs /GaAs heterostructure. The photoreflectance spectrum provided valuable information regarding the quality of the undoped GaAs, the aluminum c omposition of the AlGaAs layers, impurity diffusion, and the quantum w ell widths. Successive layer removal aided with the identification of some photoreflectance features and provided insight into the electrica l transport properties of the heterostructure. Quantum well widths obt ained from PR lineshape fits are compared with layer thicknesses measu red from cross-sectional transmission electron micrographs.