Raman and photoluminescence properties of un-/ion-doped β-Ga2O3 single-crystals prepared by edge-defined film-fed growth method

In this paper, β-Ga2O3 single-crystal with three different (100), (010) and (001) orientations and Si-/Mg-/Fe-/Sn-doped are synthesized by EFG method. β-Ga2O3 is investigated by confocal Raman and PL spectroscopy. Raman results indicated that 3D Ga2O3 substrates in the cases of un-/ions-doped growth have superior crystallinity and high uniformity. The possible reasons for the shift and broadening of vibration modes at the typical Ag (3), Ag (6) and Ag (10) mode are mainly caused by ions doping. Ga2O3(001) has a stronger vibration and translation mode of GaIO4 chain at the Ag (3) mode, in contrast to un-doped (100)/(010) planes. The Ag (10) mode change in Mg-doped (100) is significant, which means that Mg atoms are the most likely to substitute GaII atoms in the center of GaIIO6 octahedron. In PL spectroscopy, Sn-doped samples show wider blue-green emission in the range of 350–650 nm, which are related to the defect emission of Ga2O3 and Sn-doped nsnp-ns2 transition.