2022/02/09 by Fernando P. Sabino, Intuon Chatratin, Sabino, Fernando P. +5
Materials Science · #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Ga2O3 and related materials #Materials Science (cond-mat.mtrl-sci) #ZnO doping and properties
paper · pdf · doi:10.48550/arxiv.2202.04698
openalex publication_date 2022/02/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Semiconductors with wide band gap (3.0 eV), high dielectric constant (> 10), good thermal dissipation, and capable of n- and p-type doping are highly desirable for high-energy power electronic devices. Recent studies indicate that \rm ZnGa2O4 may be suitable for these applications, standing out as an alternative to \rm Ga2O3. The simple face centered cubic spinel structure of \rm ZnGa2O4 results in isotropic electronic and optical properties, in contrast to the large anisotropic properties of the β-monoclinic \rm Ga2O3. In addition, \rm ZnGa2O4 has shown, on average, better thermal dissipation and potential for n- and p-type conductivity. Here we use density functional theory and hybrid functional calculations to investigate the electronic, optical, and point defect properties of \rm ZnGa2O4, focusing on the possibility for n- and p-type conductivity. We find that the cation antisite \rm GaZn is the lowest energy donor defect that can lead to unintentional n-type conductivity. The stability of self-trapped holes (small hole polarons) and the high formation energy of acceptor defects make it difficult to achieve p-type conductivity. However, with excess of Zn, forming \rm Zn(1+2x)Ga2(1-x)O4 alloys display an intermediate valence band, facilitating p-type conductivity. Due to the localized nature of this intermediate valence band, p-type conductivity by polaron hopping is expected, explaining the low mobility and low hole density observed in recent experiments.