Second-order Raman scattering in InAs

Abstract

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 (${\ensuremath{\Gamma}}_{1}$, ${\ensuremath{\Gamma}}_{15}$, and ${\ensuremath{\Gamma}}_{12}$). ${\ensuremath{\Gamma}}_{12}$ is found negligible. ${\ensuremath{\Gamma}}_{1}$ dominates the 2TA scattering, whereas other regions of the spectra show both ${\ensuremath{\Gamma}}_{1}$ and ${\ensuremath{\Gamma}}_{15}$ symmetries. The ${\ensuremath{\Gamma}}_{1}$ 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.