论文标题
ISVORENT掺杂对IV组半导体的电子带结构的影响
The effect of isovalent doping on the electronic band structure of group IV semiconductors
论文作者
论文摘要
除SIGE外，在理论上和实验上，IV组半导体的带隙工程尚未得到很好的探索。最近，GESN引起了很多关注，因为可能在该合金中获得直接带隙，从而使其适合轻型发射器。其他IV组的合金也可能具有对设备应用有用的材料特性，从而扩大了IV组的带隙工程空间。在这项工作中，研究了所有IV组半导体合金的电子带结构。十二个可能的A：B合金，其中A是半导体的宿主（A = C，SI和GE），B是一种稀释型（B = C，SI，GE，SN和PB）的二元掺杂剂（B = C，SI，GE，SN和PB），在整个Brillouin Zone（BZ）中的稀释型（0.8％）中进行了稀释型（0.8％），并在整个Brillouin Zone（BZ）中进行了分析。使用最先进的方法（例如元GGA函数）和从大型超级电池展开的频谱方法的密度函数理论用于获得频带结构中与dopant相关的变化，尤其是BZ的L（x）点处的γ点和间接带隙。还进行了几何扭曲和电子相互作用的贡献分析。此外，在GE：B（B = C，SN和Pb）合金中获得直接基本间隙的背景下讨论了所获得的结果，以及C：B（B = SN和PB）和GE：C中的中间带形成。还观察到了定位效应的增加：用较大的共价半径的掺杂剂和具有较小半径掺杂剂的合金的强掺杂剂稀释的合金的强孔定位。最后，结果表明，将Si和GE与IV组的其他元素合金和GE是增强IV组半导体功能的一种有希望的方法。
The band gap engineering of group IV semiconductors has not been well explored theoretically and experimentally, except for SiGe. Recently, GeSn has attracted much attention due to the possibility of obtaining a direct band gap in this alloy, thereby making it suitable for light emitters. Other group IV alloys may also potentially exhibit material properties useful for device applications, expanding the space for band gap engineering in group IV. In this work the electronic band structure of all group IV semiconductor alloys is investigated. Twelve possible A:B alloys, where A is a semiconducting host (A = C, Si, and Ge) and B is an isovalent dopant (B = C, Si, Ge, Sn, and Pb), were studied in the dilute regime (0.8%) of the isovalent dopant in the entire Brillouin zone (BZ), and the chemical trends in the evolution of their electronic band structure were carefully analyzed. Density functional theory with state-of-the-art methods such as meta-GGA functionals and a spectral weight approach to band unfolding from large supercells was used to obtain dopant-related changes in the band structure, in particular the direct band gap at the Γ point and indirect band gaps at the L(X) points of the BZ. Analysis of contributions from geometry distortion and electronic interaction was also performed. Moreover, the obtained results are discussed in the context of obtaining a direct fundamental gap in Ge:B (B = C, Sn, and Pb) alloys, and intermediate band formation in C:B (B = Sn and Pb) and Ge:C. An increase in localization effects is also observed: a strong hole localization for alloys diluted with a dopant of a larger covalent radius and a strong electron localization for alloys with a dopant of smaller radius. Finally, it is shown that alloying Si and Ge with other elements from group IV is a promising way to enhance the functionality of group IV semiconductors.
