Raman scattering by LO-phononplasmon coupled modes in Ga1¿xInxAsySb1¿y : the role of Landau damping
James E. Maslar, Ramon Cusco, Esther Alarcon-Llado, Luis Artus, Wilbur S. Hurst
We present a detailed investigation of the phonons and LO-phononplasmon coupled modes in the Ga1−x InxAsy Sb1−y alloy by means of Raman scattering. A generalization of the dielectric Raman lineshape model to quaternary alloys is described and used to analyze the Raman spectra of a set of ntype Ga1−x InxAsySb1−y layers with x = 0.15, y = 0.13, and electron densities ranging from 2.8×1017 to 3.7 × 1018 cm−3. Landau-damping effects are found to be essential to correctly describe the coupled modes that occur in the phonon frequency range. Differences in the electron density dependence of these modes between 80 K and room temperature are observed and attributed to different Landaudamping regimes. The plasmonlike L+ mode is observed to shift to lower frequencies when the temperature is increased from 80 K to room temperature. This frequency shift is explained in terms of thermal population of the L valleys.
, Cusco, R.
, Alarcon-Llado, E.
, Artus, L.
and Hurst, W.
Raman scattering by LO-phonon–plasmon coupled modes in Ga1¿xInxAsySb1¿y : the role of Landau damping, Physical Review B, [online], https://doi.org/10.1103/PhysRevB.81.195212
(Accessed February 26, 2024)