Characterization of carrier concentration and mobility of GaN bulk substrates by Raman scattering and infrared reflectance spectroscopies

Abstract

n-Type GaN bulk substrates with carrier concentrations (n) of 1016–1020 cm−3 were characterized by Raman scattering (350–5000 cm−1) and infrared reflectance (400–5000 cm−1) spectroscopies. Experimental spectra were fitted with the curves calculated from the dielectric function and carrier concentration and mobility of the GaN bulk. The obtained values agree well with the values from Hall-effect measurements for n of 1016–1019 cm−3 in Raman scattering measurements and for n of 1018–1020 cm−3 in infrared reflectance measurements.