Modulation in structural and electronic properties of 2D Ga2O3 by chemical passivation

Abstract

Wide-bandgap semiconductor β-Ga₂O₃ with fascinating optical–electrical characteristics and low-cost processed fabrication has gain wide attention. Recently, exfoliated quasi two-dimensional (2D) Ga₂O₃ with excellent properties has received both experimental and theoretical attention. However, the stability of 2D Ga₂O₃ is reduced by the abrupt absence of interlayer interactions, and the possibility of p-type conduction for 2D Ga₂O₃ is not clear up to now. Herein, we investigated atom-passivated 2D Ga₂O₃ using first-principles, the atomic configurations, formation energies, and electronic structures were calculated and examined. The results indicate that the dangling bonds on the surfaces are effectively passivated and the stability is elevated for hydrofluorinated Ga₂O₃, which possesses a wide direct bandgap (5.547 eV) and ultra-high carrier mobility (∼10³ cm² V⁻¹ s⁻¹). The acoustic phonon-limited mobility μ reveals the potential of bipolar transport property (μ_eb/μ_hb is ∼2.45) for 2D Ga₂O₃ along the b direction. Furthermore, layer-dependent properties of hydrofluorinated 2D Ga₂O₃ were discussed. Our study offers an effective approach to modify the stability and electronic properties of 2D Ga₂O₃, and supplies a new strategy to realize p-type conducting Ga₂O₃.