【Epitaxy Papers】Acceptor-doped mist CVD Cr₂O₃ films grown on sapphire and (100) β-Ga₂O₃ substrates

Abstract

      Epitaxial films of Cr₂O₃ doped with various concentrations of Mg, Ni and Cu were grown by mist chemical vapor deposition (mist-CVD) on electrically insulating sapphire substrates. The conductivity of films increases by several orders of magnitude with increasing doping level. Highly-conductive (with approximately 6 wt% of Cu) films demonstrated p-type in hot-probe tests. This allowed us to fabricate p-Cr₂O₃/n-Ga₂O₃ heterojunctions in the similar growth experiments using n-type (100) β-Ga₂O₃ plates cleaved from crystals grown by Czochralski method. The capacitance-voltage, current-voltage, admittance spectra, deep levels transient spectra (DLTS) of the heterojunctions indicate the existence of good rectification and low leakage current of the heterojunction with presence of interfacial states with levels close to E_c-0.15 eV, E_c-0.21 eV, E_c-0.45 eV on the Ga₂O₃ side. The properties of Cr₂O₃:Cu/β-Ga₂O₃ heterojunctions are compared with the properties we observed for NiO/Ga₂O₃ heterojunctions and with the published results for p-Cr₂O₃(Mg)/β-Ga₂O₃ heterojunctions.

DOI：

https://doi.org/10.1016/j.jallcom.2026.187824