Polarized Raman spectra in β-Ga2O3 single crystals

• Polarized Raman spectra were measured from β-Ga2O3 substrates.
• The substrates were prepared by either the floating zone growth or edge-defined film-fed growth methods.
• The polarization selection rules were perfectly reproduced in the spectra.
• This is the first experimental observation of the complete set of polarized Raman spectra of β-Ga2O3.
• The results imply high crystalline quality of the present substrates.

Polarized Raman spectra were measured from (010) Mg-doped, (100) Si-doped, and (001) unintentionally-doped β-Ga2O3 substrates prepared by either the floating zone growth or edge-defined film-fed growth methods. The Ag and Bg Raman active modes were perfectly separated in the spectra according to the polarization selection rules. To the best of our knowledge, this is the first experimental observation of a complete set of polarized Raman spectra of β-Ga2O3. The results are ensured by the high uniformity of crystalline orientation and surface flatness of the present substrates.