RESONANT RAMAN-SCATTERING STUDIES OF MULTILAYER (IN, GA, AL) (AS, SB) HETEROSTRUCTURES WITH INAS QUANTUM-WELLS

Raman scattering effects have been used to study phonon properties of complex multilayer (In, Ga, Al) (As, Sb) heterostructures with InAs quantum wells grown by molecular beam epitaxy on GaAs and GaSb substrates. Raman scattering in the region of folded acoustic phonons gives information on the periodicity of cladding superlattices and the abruptness of their interfaces. Raman scattering by InAs phonon modes due to an InAs quantum well are strongly enhanced under optical excitation in resonance with the E1 band gap of InAs. Interface modes of InSb are detected in resonant Raman scattering, in agreement with the intended interface bond controlled by the beam supply sequence during growth. Resonant excitation results also in the observation of Raman scattering by a collective intersubband plasmon mode due to a two dimensional electron gas in the InAs quantum well. It is shown that a detailed analysis of complex multilayer structures can be performed based upon resonant Raman experiments which agrees fairly well with double crystal x-ray diffraction and galvanomagnetic studies.