We report a positron annihilation study using state-of-the-art experimental and theoretical methods in n-type and semi-insulating $\beta -{\text{Ga}}_2{\mathrm{O}}_3$. We utilize the recently discovered unusually strong Doppler broadening signal anisotropy of $\beta -{\text{Ga}}_2{\mathrm{O}}_3$ in orientation-dependent Doppler broadening measurements, complemented by temperature-dependent positron lifetime experiments and first principles calculations of positron–electron annihilation signals. We find that split Ga vacancies dominate the positron trapping in $\beta -{\text{Ga}}_2{\mathrm{O}}_3$ single crystals irrespective of the type of dopant or conductivity, implying concentrations of at least $1\times 10^{18}\hspace{0.17em}\mathrm{c}{\mathrm{m}}^{-3}$.

中文翻译：

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分裂Ga空位in-型和半绝缘β-Ga2O3单晶

我们报告了在n型和半绝缘中使用最新的实验和理论方法进行的正电子an灭研究$\beta --{\text{嘎}}_2{\mathrm{Ø}}_3$。我们利用最近发现的异常强的多普勒展宽信号各向异性$\beta --{\text{嘎}}_2{\mathrm{Ø}}_3$在与方向有关的多普勒展宽测量中，辅之以与温度有关的正电子寿命实验和正电子-电子an灭信号的第一原理计算。我们发现分裂的Ga空位占主导的正电子陷阱$\beta --{\text{嘎}}_2{\mathrm{Ø}}_3$ 单晶，与掺杂剂类型或电导率无关，这意味着至少浓度为 $\mathrm{1个}\times \mathrm{1个}{0}^{\mathrm{18岁}}\hspace{0.17em}\mathrm{C}{\mathrm{米}}^{-3}$。