Abstract:

β-Ga₂O₃ crystal is a novel oxide semiconductor with wide bandgap, but its intrinsic conductive capability is poor. Ion doping is an effective way to regulate conductivity, transparency and crystallinity of the crystal. Transparent blue In:Ga₂O₃ single crystal with the dimension ofφ8 mm×50 mm was grown by optical floating zone method. The as-grown crystal is of good crystallization quality. After doping In³⁺ ion, β-Ga₂O₃ crystal has strong infrared absorption, and its thermal conductivity slightly decreases. At room temperature, the electrical conductivity and carrier concentration of as-grown In:Ga₂O₃ crystal are 4.94×10^-4 S/cm and 1.005×10¹⁶ cm^-3, respectively, which are approximately one order magnitude higher than that of undoped β-Ga₂O₃ crystal. The electrical property of In:Ga₂O₃ crystal is sensitive to heat treatment. After annealing at 1200℃ in air or in argon, its electrical conductivity decreases. These experimental results suggest that In³⁺ ion doping can improve the electrical property of β-Ga₂O₃ single crystal.

Key words: In:Ga₂O₃ single crystal, optical floating zone method, electrical conductivity