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人工晶体学报 ›› 2022, Vol. 51 ›› Issue (1): 49-55.

• 研究论文 • 上一篇    下一篇

P掺杂6H-SiC的第一性原理研究

黄思丽, 谢泉, 张琴   

  1. 贵州大学大数据与信息工程学院,新型光电子材料与技术研究所,贵阳 550025
  • 收稿日期:2021-09-26 出版日期:2022-01-15 发布日期:2022-02-09
  • 通讯作者: 谢泉,教授。E-mail:qxie@gzu.edu.cn
  • 作者简介:黄思丽(1996—),女,贵州省人,硕士研究生。E-mail:2508708441@qq.com
  • 基金资助:
    贵州大学智能制造产教融合创新平台及研究生联合培养基地(2020-520000-83-01-324061);国家自然科学基金(61264004);贵州省高层次创新型人才培养项目(黔科合人才(2015)4015)

First-Principles Study of P-Doped 6H-SiC

HUANG Sili, XIE Quan, ZHANG Qin   

  1. Institute of Advanced Optoelectronic Materials and Technology, College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China
  • Received:2021-09-26 Online:2022-01-15 Published:2022-02-09

摘要: 采用基于密度泛函理论的第一性原理赝势平面波法,计算未掺杂与P替换Si、C以及P间隙掺杂6H-SiC的电子结构与光学性质。结果显示未掺杂的6H-SiC是带隙为2.052 eV的间接带隙半导体,P替换Si、C掺杂以及P间隙掺杂6H-SiC带隙均减小,分别为1.787 eV、1.446 eV和0.075 eV,其中P间隙掺杂带隙减小幅度最大。P替换掺杂6H-SiC使得费米能级向导带移动并插入导带中,呈n型半导体。P间隙掺杂价带中的一条能级跨入费米能级,因此在禁带中出现一条P 3p杂质能级,P间隙掺杂6H-SiC转为p型半导体。替换与间隙掺杂使得6H-SiC的介电函数实部增大,介电函数虚部、吸收光谱、反射光谱与光电导率红移,其中P间隙掺杂效果最佳。通过P掺杂材料的电导率增强,对红外波段的利用率明显提高,为6H-SiC在红外光电性能方面的应用提供有效的理论依据。

关键词: 间隙掺杂, 6H-SiC, 带隙, 介电函数, 第一原理, 电子结构, 光学性质

Abstract: The electronic structure and optical properties of intrinsic 6H-SiC, P substituted for Si, C doped and P interstitial doped 6H-SiC were calculated by the first-principles pseudopotential plane wave method based on density functional theory. The results indicate that intrinsic 6H-SiC is an indirect band gap semiconductor with a band gap of 2.052 eV. The band gaps of the P substituted for Si, C doped and P interstitial doped 6H-SiC decrease to 1.787 eV, 1.446 eV and 0.075 eV, respectively. The interstitial doping band gap decreases the most. P substitutional doped 6H-SiC causes the Fermi level guide band to move and insert into the conduction band, and the 6H-SiC becomes an n-type semiconductor. One level of P interstitial doping valence band crosses into Fermi level, so a P 3p impurity level appears in the gap band, and 6H-SiC turns into p-type semiconductor. Substitutional and interstitial doping increase the real part of dielectric function of 6H-SiC, while the imaginary part of dielectric function, absorption spectrum, reflection spectrum and photoconductivity redshift. Among them, P interstitial doped 6H-SiC has the best effect. The conductivity of the material is enhanced and the utilization rate of the material in the infrared band is obviously improved by P doping. The results provide effective theoretical basis for the application of 6H-SiC in infrared photoelectric performance.

Key words: gap doping, 6H-SiC, band gap, dielectric function, first-principle, electronic structure, optical property

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