Cyclotron-resonance studies in relaxed InxGa1-xAs (0

Abstract

By the techniques of far-infrared optically detected cyclotron resonance and magnetophotoconductivity, we have performed cyclotron-resonance measurements on relaxed ${\mathrm{In}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As epitaxial layers with a wide range of composition. The measured electron effective mass as a function of indium composition has been analyzed with the five-band k\ensuremath{\cdot}p calculation. It is found that the effect of disorder-induced conduction--valence-band mixing must be included in order to resolve the discrepancy between the results of the k\ensuremath{\cdot}p theory and experiments. The linewidths of cyclotron resonance and photoluminescence as a function of alloy composition have also been studied. Comparing with the measurement of double-crystal x-ray diffraction, we point out that the cyclotron-resonance and photoluminescence signals in ${\mathrm{In}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As alloys are dominated by the dislocation scattering. In addition, we show that the quality of a ternary epilayer is not only influenced by the lattice mismatch; the surface migration lengths of the cation atoms in the initial growth stage also play a very important role.