Absorption and Reflection of Vapor Grown Single Crystal Platelets of β-Ga₂O₃

Abstract

Absorption and reflection spectra of β-Ga2O3 are measured with polarized light in the wavelength region near its absorption edge. The crystals of β-Ga2O3 are grown by using a Ga/HCl/O2/Ar vapor reaction system. The platelike crystals of β-Ga2O3 have (100), (010), and (001) surfaces, and the major surface is (100). The energies of the absorption edge are observed to be 4.90 eV for E//b, 4.54 eV for E//c, and 4.56 eV for E⊥b&c at room temperature. The energies for E//b and for E//c at 77 K are larger than those at room temperature by 40 meV and 220 meV, respectively. Reflection minima are observed at 5.06 eV and 5.30 eV for E//b, and at 4.63 eV and 5.30 eV for E//c at room temperature.

Theoretical and experimental investigation of optical absorption anisotropy in β-Ga2O3

“…This significant shift of the absorption edge is a direct evidence for anisotropy and confirms the previous observations in [21,22].…”

(InxGa1−x)2O3alloys for transparent electronics

“…In spite of its large band gap of 4.76 eV, 4 high levels of n-type conductivity have been reported, with mobilities up to 150 cm 2 /Vs and carrier concentrations exceeding 10 18 cm −3 , 5 making the material a candidate TCO in the UV wavelength region.…”

Dielectric tensor of monoclinic Ga2O3 single crystals in the spectral range 0.5–8.5 eV

“…8,[14][15][16][17][18][19] However, rotation domains present in the thin films and the inferior crystal structure compared to a single crystal prohibited the determination of the tensor components and only an effective dielectric function was measured. Experiments on single crystals are rare and mainly limited to transmission 6,20 and absorption 6,7,21 measurements. From such data the entire dielectric tensor cannot be determined and only the absorption edges as well as the refractive index in the transparent spectral range were deduced.…”