As an ultrawide bandgap semiconductor, gallium oxide (Ga₂O₃) has superior physical properties and has been an emerging candidate in the applications of power electronics and deep-ultraviolet optoelectronics. Despite numerous efforts made in the aspect of material epitaxy and power devices based on β-Ga₂O₃ with rapid progresses, the fundamental understanding of defect chemistry in Ga₂O₃, in particular, acceptor dopants and carrier compensation effects, remains a key challenge. In this focused review, we revisited the principles of popular approaches for characterizing defects in semiconductors and summarized recent advances in the fundamental investigation of defect properties, carrier dynamics and optical transitions in Ga₂O₃. Theoretical and experimental investigations revealed the microstructures and possible origins of defects in β-Ga₂O₃ bulk single crystals, epitaxial films and metastable-phased α-Ga₂O₃ epilayers by the combined means of first-principle calculation, deep level transient spectroscopy and cathodoluminescence. In particular, defects induced by high-energy irradiation have been reviewed, which is essential for the identification of defect sources and the evaluation of device reliability operated in space and other harsh environments. This topic review may provide insight into the fundamental properties of defects in Ga₂O₃ to fully realize its promising potential in practical applications.

作为超宽带隙半导体，氧化镓（Ga ₂ O ₃）具有优异的物理性能，并已成为电力电子和深紫外光电子学应用中的新兴候选材料。尽管在基于材料外延和功率器件的方面制得许多努力β -Ga ₂ ö ₃具有快速进展，基本缺陷化学的理解通过在Ga ₂ ö ₃尤其是受主掺杂剂和载流子补偿效应仍然是关键挑战。在本次重点综述中，我们重新介绍了表征半导体中缺陷的流行方法的原理，并总结了Ga ₂ O ₃中缺陷性质，载流子动力学和光学跃迁的基础研究的最新进展。理论和实验研究表明，β- Ga ₂ O ₃块状单晶，外延膜和亚稳相α - Ga ₂ O ₃的微观结构和缺陷的可能成因。通过第一性原理计算，深层瞬态光谱和阴极发光的组合手段来形成外延层。特别地，已经审查了由高能辐照引起的缺陷，这对于识别缺陷源以及评估在空间和其他恶劣环境下运行的设备可靠性至关重要。本主题综述可能会提供有关Ga ₂ O ₃中缺陷基本性质的见解，以充分实现其在实际应用中的潜力。