Internal-stress effects on Raman spectra of In x Ga 1 <mml:mi mathvariant="…
1988; American Physical Society; Volume: 38; Issue: 5 Linguagem: Inglês
10.1103/physrevb.38.3280
ISSN1095-3795
AutoresShūichi Emura, Shun‐ichi Gonda, Yūichi Matsui, Hideki Hayashi,
Tópico(s)Semiconductor materials and interfaces
ResumoRaman spectra of ${\mathrm{In}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As are observed over a wide range of composition. A GaAs-like mode frequency \ensuremath{\omega} is found to vary with the composition x as \ensuremath{\omega}=-32.4${x}^{2}$-18.6x+290.0 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. The internal stresses due to lattice mismatch are evaluated from the deviation of the GaAs-like LO mode frequency from the above experimental equation for small lattice mismatch. An increase is found in the internal stress toward the interface from the 5000-A\r{}-thick surface layer. The stress effects on the lattice vibrations of the optical mode are discussed from a microscopic point of view.
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