Resonance Raman scattering in HgTe: TO-phonon and forbidden-LO-phonon cross section near the E₁ gap

Abstract

In this paper we present Raman intensity variation of the TO phonon and the forbidden LO phonon in HgTe. We evaluate the optical-phonon deformation potentials near the E₁ gap (d₁₀⁵=24 eV and d₃₀⁵=20 eV). The differences that arise as a consequence of the inverted band structure of HgTe are discussed and it is shown that the standard macroscopic formalism for Raman susceptibility for the TO-phonon mode in terms of linear susceptibility can be applied to HgTe also. Investigation of forbidden-LO-phonon intensity reveals that impurity-induced scattering is dominant and interband electron-phonon scattering has to be explicitly included to account for its variation with laser wavelength.