锗锡浓度对硅锗锡合金性能影响的研究  

Study on the effect of germanium-tin concentration on the properties of silicon-germanium-tin alloys

作　　者：顾永顺 温淑敏[1] GU Yong-Shun;WEN Shu-Min(College of Science,Inner Mongolia University of Technology,Hohhot 010051,China)

机构地区：[1]内蒙古工业大学理学院,呼和浩特010051

出　　处：《原子与分子物理学报》2025年第5期163-174,共12页Journal of Atomic and Molecular Physics

基　　金：2023年校级“大学生创新创业训练计划”项目(2023093019)。

摘　　要：由于SiGeSn合金材料其具有高的载流子迁移率和较长的载流子寿命,并且其结构具有较高的热力学稳定性,所以在光电子领域中是一种具有非常大应用潜力的半导体材料.本文采用密度泛函理论中的广义梯度近似GGA+U的方法,构建并计算了本征半导体Si_(96)与五组掺杂模型Si_(92)Ge_(2)Sn_(2)、Si_(88)Ge_(4)Sn_(4)、Si_(84)Ge_(6)Sn_(6)、Si_(80)Ge_(8)Sn_(8)、Si_(76)Ge_(10)Sn_(10)的电子结构及光学性质.通过对计算结果的分析可知,Ge,Sn的加入使得Si材料的带隙宽度减小,并且发生了由间接带隙向直接带隙的转变;Ge,Sn浓度最高的SiGeSn合金的形成能相对较高,稳定性相较于Ge,Sn含量低的材料较差;随着Ge,Sn掺杂浓度的提高,电子态密度图显示出越来越明显的杂化现象,并且态密度的峰值主要有Si原子的s轨道提供;Ge,Sn浓度的提高还使得SiGeSn合金的吸收系数在可见光及近红外区域内增加、反射率在可见光及以上波段范围内提高、折射率变低、消光系数曲线向红外区域移动等光学性质变化,表明可以通过调节Ge,Sn浓度来获得合适的光学特性,这为SiGeSn半导体在红外区域光电材料和器件的应用上提供了研究方向.SiGeSn alloy material is a semiconductor material with great application potential in the field of optoelectronics because of its high carrier mobility,long carrier lifetime,and high thermodynamic stability of its structure.In this paper,the electronic structure and optical properties of intrinsic semiconductor Si_(96) and five groups of doping models Si_(92)Ge_(2)Sn_(2),Si_(88)Ge_(4)Sn_(4),Si_(84)Ge_(6)Sn_(6),Si_(80)Ge_(8)Sn_(8) and Si_(76)Ge_(10)Sn_(10) are constructed and calculated by using the generalized gradient approximation GGA+U method based on density functional theory.Through the analysis of the calculation results,it can be seen that the addition of Ge and Sn reduces the band gap width of Si materials,and the transformation from indirect band gap to direct band gap occurs.In addition,the SiGeSn alloy with the highest concentration of Ge and Sn has relatively high formation energy,and its stability is worse than that of the material with low Ge and Sn content.With the increase of Ge and Sn doping concentrations,the electronic density of states(DES)shows more and more obvious hybridization,and the peak value of the density of states is mainly provided by the s orbital of Si atoms.The increase of Ge and Sn concentrations also increases the absorption coefficient of SiGeSn alloy in the visible and near-infrared regions,the reflectivity increases in the visible and above wavelength ranges,and the refractive index decreases,which makes the extinction coefficient curve move to the infrared region and the optical properties change,indicating that suitable optical properties can be obtained by adjusting the Ge and Sn concentrations,which provides a research direction for SiGeSn semiconductors in the application of optoelectronic materials and devices in the infrared region.

关 键 词：SiGeSn 电子特性 光学性质 

分 类 号：O471[理学—半导体物理]