Abstract The electronic structures and the optical gaps of Si-doped β-Ga2O3 with different Si concentration are studied by the generalized gradient approximation combined Hubbard U (GGA + U) method based on the density functional theory. The doping formation energy reveals that Si-doped β-Ga2O3 is mainly realized in the form of substitutional Si rather than interstitial Si, and tends to obtain effective doping under O-poor condition. As substitutional Si concentration increases, the optical gap of Si-doped β-Ga2O3 increases while the bandgap narrows, which are mainly attributed to the Burstein-Moss effect and the many-body renormalization effect. The bandgap widening Δ E BM and the bandgap narrowing Δ E BGN of Si-doped β-Ga2O3 as a function of Si carrier concentration can be described by Pisarkiewicz’s model and Schmid’s empirical expression, respectively.

中文翻译：

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Si浓度对Si掺杂β-Ga2O3电子结构和光隙的影响

摘要 采用基于密度泛函理论的广义梯度近似组合Hubbard U(GGA+U)方法研究了不同Si浓度的Si掺杂β-Ga2O3的电子结构和光学能隙。掺杂形成能表明，Si掺杂的β-Ga2O3主要以置换Si而不是间隙Si的形式实现，并且在O-poor条件下倾向于获得有效的掺杂。随着置换Si浓度的增加，Si掺杂的β-Ga2O3的光隙增加而带隙变窄，这主要归因于Burstein-Moss效应和多体重整化效应。Si 掺杂 β-Ga2O3 的带隙加宽 Δ E BM 和带隙变窄 Δ E BGN 作为 Si 载流子浓度的函数可以通过 Pisarkiewicz 模型和 Schmid 的经验表达式来描述，