Raman ressonante em superredes de InO, 22GaD, 78As/GaAs tensionados

AUTOR(ES)
DATA DE PUBLICAÇÃO

1997

RESUMO

Optical and x-ray measuremnts were performed on several InxGa1-xAs/GaAs strained-layer superlattices. One of the superlattices was selected for pressure-induced Resonant Raman Scattering studies. The resonance conditions were attained by tuning the energy gaps of the material to the scattered light energy. Two resonant enhancements were observed for either the LO or the 2LO cross section. These enhancement correspond to the first transition energies in the barrier and well, respectively. As electronic states of both constituent layers produce resonance with the same phonon, it cannot be confined in either of these layers. Triple resonance conditions yielded well defined maxima in the 2LO profile. In order to determine the superlattice for which the triple resonance conditions held, we performed a previous characterization of the samples. This characterization included phoreflectance measurements and analisis in terms of built-in fields. The results delivered the heavy-hole and light-hole energies of our interest. A calculation of these levels were performed simultaneously. One of the parameters in thi8 calculations was the strain in each constituent layer. The strains were measured in the E1, E1 + D1, energy region of GaAs. This determination is particularly affective for InxGa1-xAs/GaAs superlattices

ASSUNTO(S)

roman ressonante superestrutura como material efeito de

ACESSO AO ARTIGO

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