CuSCN的第一性原理研究

发布时间：2018-01-18 23:55

本文关键词： 密度泛函理论宽禁带半导体 CuSCN WIEN2K 光学性质　出处：《燕山大学》2015年硕士论文　论文类型：学位论文

【摘要】：Cu SCN作为一种重要的宽禁带半导体材料。由于较高透光性和光电导率,使其成为透明电子器件的理想选择,尤其在染料敏化异质结太阳能电池(DSH)和极薄吸附太阳能电池(ETA)中已得到广泛应用。同时具有的价格低廉、制备工艺简便等优点,使其在船底材料、果树防护涂层,测定微量元素、抗坏血酸等方面都有应用。本文利用基于密度泛函理论的WIEN2K和CASTEP软件,计算研究了六方晶系β相和正交晶系α相两种结构Cu SCN的态密度、能带结构,以及介电函数、吸收系数、光导率、折射率、消光系数、反射率及能量损失函数等光学性质。研究了晶胞中原子弛豫对六方晶系β相与正交晶系α相两种结构Cu SCN性能的影响,并将计算结果与实验测量值进行了比较。本论文的主要研究内容如下:首先,论文对Cu SCN的研究背景和现状进行了简要阐述,介绍了其研究现状和应用前景,根据其研究现状提出了本课题的研究内容。其次,利用第一性原理,对六方晶系β相和正交晶系α相的Cu SCN进行结构优化,研究了原子弛豫对其相关性质如:态密度、能带结构及光学性质的影响,并与相关的实验测量结果进行了比较。分析了m BJ交换关联势用于两种结构Cu SCN能带带隙计算的准确性。最后,我们比较研究了六方晶系β相与正交晶系α相两种结构Cu SCN的能带性质、紫外光吸收率和光导率的差异,以及在xx方向和zz方向上两种结构Cu SCN的光学性质存在的差异。研究分析了六方晶系β相与正交晶系α相Cu SCN相比在应用于太阳能电池和紫外光探测器方面存在的优势。从理论方面对Cu SCN的应用前景作出了预测。
[Abstract]:As an important wide band gap semiconductor material, Cu SCN is an ideal choice for transparent electronic devices due to its high transmittance and optical conductivity. Especially, it has been widely used in dye sensitized heterojunction solar cells (DSH) and extremely thin adsorbed solar cells (ETAs). At the same time, it has the advantages of low cost and simple preparation process. It can be used in materials of ship bottom, protective coating of fruit trees, determination of trace elements, ascorbic acid, etc. In this paper, WIEN2K and CASTEP software based on density functional theory are used. The density of state, band structure, dielectric function, absorption coefficient, photoconductivity, refractive index and extinction coefficient of Cu SCN with hexagonal 尾 phase and orthogonal 伪 phase are calculated and studied. Optical properties such as reflectivity and energy loss function were studied. The effect of atomic relaxation on the properties of Cu SCN with hexagonal 尾 phase and orthorhombic 伪 phase was investigated. The main contents of this thesis are as follows: firstly, the research background and current situation of Cu SCN are briefly described. This paper introduces its research status and application prospect, and puts forward the research content of this subject according to its research status. Secondly, the first principle is used. The structure of Cu SCN in hexagonal 尾 phase and orthorhombic 伪 phase was optimized. The effects of atomic relaxation on the properties such as density of states, band structure and optical properties were studied. The accuracy of the mBJ exchange correlation potential applied to the calculation of the band gap of Cu SCN in two kinds of structures is analyzed. The differences of band properties, UV absorptivity and photoconductivity of Cu SCN with hexagonal 尾 phase and orthorhombic 伪 phase are compared. The optical properties of Cu SCN with two structures in xx direction and ZZ direction are different. The 尾 phase of hexagonal crystal system and 伪 phase of orthogonal system are studied and analyzed. Compared with the application of SCN in solar cells and UV detectors, the application prospect of Cu SCN is predicted theoretically.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304

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