Signatures of free carriers in Raman spectra of cubic ln_2O_3

摘要

We discuss the influence of free carriers on the Raman scattering in n-type In2O3. For high-quality cubic single crystals, electronic single-particle excitations are revealed as a relatively broad Raman feature in the frequency range below 300 cm(-1). Furthermore, discrete phonon lines in the same frequency range exhibit asymmetric lineshapes characteristic for Fano resonances. The two observed spectral features contain the potential to be utilized for the quantitative determination of the free carrier concentration in n-type In2O3 using Raman spectroscopy as a contactless experimental technique.