Blueshifted Raman scattering and its correlation with the †110‡ growth direction in gallium oxide nanowires

The Raman spectrum of gallium oxide -Ga2O3 nanowires with 001 growth direction is identical to that of the bulk Ga2O3 Y. C. Choi et al. Adv. Mater. 12, 746 2000 while that of -Ga2O3 nanowires with 401̄ growth direction is redshifted by 4–23 cm−1 Y. H. Gao et al. Appl. Phys. Lett. 81, 2267 2002 . Here we report the Raman and Fourier transform infrared spectra of -Ga2O3 nanowires with 110 growth direction which is blueshifted relative to the bulk spectra by 10–40 cm−1. Based on a first principles calculation of the strain dependence of Raman mode frequencies in bulk -Ga2O3, we correlate the observed frequency shifts to growthdirection-induced internal strains in the nanowires. © 2005 American Institute of Physics. DOI: 10.1063/1.2128044