Second-order Raman scattering in InAs

The second-order Raman spectra of crystalline InAs have been analyzed both at 100 and 330 K to obtain the three irreducible components of the Raman tensor (Γ₁, Γ₁₅, and Γ₁₂). Γ₁₂ is found negligible. Γ₁ dominates the 2TA scattering, whereas other regions of the spectra show both Γ₁ and Γ₁₅ symmetries. The Γ₁ component is compared with recent calculations of the overtones of the two-phonon density of states based on an overlap-valence-shell model. Good agreement is obtained. Although neutron data are not available, all the bands of the second-order Raman spectra are assigned.