Effects of Cu, Zn Doping on the Structural, Electronic, and Optical Properties of α-Ga(2)O(3): First-Principles Calculations

The intrinsic n-type conduction in Gallium oxides (Ga(2)O(3)) seriously hinders its potential optoelectronic applications. Pursuing p-type conductivity is of longstanding research interest for Ga(2)O(3), where the Cu- and Zn-dopants serve as promising candidates in monoclinic β-Ga(2)O(3). However, the theoretical band structure calculations of Cu- and Zn-doped in the allotrope α-Ga(2)O(3) phase are rare, which is of focus in the present study based on first-principles density functional theory calculations with the Perdew–Burke–Ernzerhof functional under the generalized gradient approximation. Our results unfold the predominant Cu(1+) and Zn(2+) oxidation states as well as the type and locations of impurity bands that promote the p-type conductivity therein. Furthermore, the optical calculations of absorption coefficients demonstrate that foreign Cu and Zn dopants induce the migration of ultraviolet light to the visible–infrared region, which can be associated with the induced impurity 3d orbitals of Cu- and Zn-doped α-Ga(2)O(3) near the Fermi level observed from electronic structure. Our work may provide theoretical guidance for designing p-type conductivity and innovative α-Ga(2)O(3)-based optoelectronic devices.