高等学校化学学报 ›› 2019, Vol. 40 ›› Issue (3): 518-527.doi: 10.7503/cjcu20180550

• 物理化学 • 上一篇    下一篇

黄铜矿型铜基硫属半导体材料的电子结构和光学性质

周和根1,2, 金华1, 郭辉瑞1, 林晶2, 章永凡2()   

  1. 1. 宜春学院化学与生物工程学院, 宜春 336000
    2. 福州大学化学学院, 福州 350116
  • 收稿日期:2019-08-03 出版日期:2019-01-24 发布日期:2019-01-24
  • 作者简介:

    联系人简介: 章永凡, 男, 博士, 研究员, 博士生导师, 主要从事光学性质与表面催化理论研究. E-mail: zhangyf@fzu.edu.cn

  • 基金资助:
    国家自然科学基金(批准号: 21563030, 21373048)资助.

Electronic Structures and Optical Properties of Cu-based Semiconductors with Chalcopyrite-type Structure

ZHOU Hegen1,2, JIN Hua1, GUO Huirui1, LIN Jing2, ZHANG Yongfan2,*()   

  1. 1. College of Chemical and Biological Engineering, Yichun University, Yichun 336000, China
    2. College of Chemistry, Fuzhou University, Fuzhou 350116, China
  • Received:2019-08-03 Online:2019-01-24 Published:2019-01-24
  • Contact: ZHANG Yongfan E-mail:zhangyf@fzu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China (Nos.21563030, 21373048).

摘要:

采用基于赝势平面波基组的密度泛函理论方法, 对具有黄铜矿结构的6种CuXY2(X=Ga, In; Y=S, Se, Te)晶体的构型、 电子结构、 线性及二阶非线性光学性质进行了研究. 结果表明, 6种CuXY2均为直接带隙半导体, 具有相似的能带结构. 当X原子相同时, 随着Y原子按S→Se→Te依次改变时, 体系的静态介电常数、 静态折射率和静态倍频系数(d36)依次递增. 在占据带中, 位于价带顶附近的能带对体系倍频效应影响最为显著, 该系列化合物的能带主要成分为Cu的3d轨道和Y原子价层p轨道; 对于空能带, 对倍频系数影响较大的是以X原子价层p轨道为主要成分的能带. 6种晶体中, CuInSe2晶体具有较高的光电导率并对太阳光具有较好的吸收性能. 综合考虑体系的双折射率和倍频效应等因素, CuGaS2和CuGaSe2 2种晶体在二阶非线性光学领域具有潜在的应用价值.

关键词: 密度泛函理论, 电子结构, 光学性质, 倍频系数, 黄铜矿

Abstract:

The density functional theory(DFT) based on the pseudo-potential plane wave basis was employed to investigate the geometries, electronic structures, linear and second-order nonlinear optical properties of the CuXY2(X=Ga, In; Y=S, Se, Te) crystals with chalcopyrite structure. The results indicate that these compounds are semiconductors with a direct gap and have similar band structures. The static dielectric constants, the refractive indices and the second harmonic generation(SHG) coefficients(d36) of these compounds increase in the sequence of S→Se→Te for the same X atom. Among the occupied bands, those states near the top of the valence band contribute mostly to the SHG effect, which are dominated by the components of Cu3d orbitals and the valence p orbitals of Y atom. While for the unoccupied bands, the bands mainly derived from valence p orbitals of X atoms have obvious influences on the SHG coefficient. Among these six crystals, CuInSe2 has high photoconductivity and better absorption of sunlight. In addition, CuGaS2 and CuGaSe2 crystal have potential applications in the second-order nonlinear optical fields based on their birefringences and SHG strengths.

Key words: Density functional theory(DFT), Electronic structure, Optical property, Second harmonic generation, Chalcopyrite

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