红外探测器件新材料的第一性原理研究

发布时间：2019-07-05 20:52

【摘要】：本文构思了一种利用新型材料的便携红外探测器,由四个模块组成。红外探测模块使用InSb红外探测器件,数据存储与调用模块使用基于ABi_2Nb_2O_9(A=Ba,Pb,Sr,Ca)的铁电存储器,数据处理分析模块使用还在理论论证中的石墨烯高性能处理器,续航模块使用VS_2基底作为催化剂的析氢反应氢电池。通过一种理论,密度泛函理论,和基于它的第一性原理方法,我们有贯穿始终的处理手段对这四个模块的四种新材料进行分析,具体分析如下:1.针对InSb(110)表面,我们用第一性原理计算方法,通过VASP软件分析了分别在In原子和Sb原子上吸附氧原子和硫原子的情况。比较计算结果,我们发现在InSb(110)表面硫吸附之后的系统性质比氧吸附之后更加稳定,这也解释了为什么工艺上要对InSb表面进行硫化处理。2.我们采用密度泛函理论第一性原理的计算方法综合地研究了ABi_2Nb_2O_9(A=Ba,Pb,Sr,Ca)体系的结构,电子性质,化学键以及自发极化。其中化学键的分析结合了bader的原子中的分子(AIM)理论。目的在于阐明ABi_2Nb_2O_9铁电体的铁电起源,理解这些材料的电子结构和极化属性随A位离子变化趋势。二,运用现代极化理论计算了SBN铁电极化并薄膜显现出大的极化原因,同时对BBN,PBN,CBN的极化强度给出一个理论的预测。3.我们调研了至今为止报告出的石墨烯结构缺陷。我们将讨论这些缺陷的形成,以及他们对石墨烯性质的影响。为了使得接下来的讨论简单明了,虽然本质上可以存在无数个种类的晶格缺陷,我们只讨论最简单的一些。我们将特别的把注意力放在单层石墨烯的缺陷,因为双层和多层石墨烯的缺陷类型已经存在于石墨之中,而且已经在很早之前就被讨论过。同时,对第一性原理计算后的态密度和能带结构做了简单的分析。4.二维VS_2纳米材料已经作为一种对析氢反应(HER)效率很高和便宜的电催化剂出现。要更进一步的改善他们在析氢反应中的性能,我们必须了解他们的催化机理以及他们在各种原始或者缺陷结构中的行为。本论文中,我们利用第一性原理计算研究了具有各种各样本征点缺陷的单层VS_2纳米片中的结构稳定性,电子特性和析氢反应的行为。与最多被研究的2H相MOS_2基面相比较,无论是2H相还是1T相的VS_2基面都展示出出众的催化活性。因为他们的金属性质。在VS_2基底上引入本征电缺陷后,我们发现一共有四种稳定缺陷在2H相中(也就是Sad,Svac,Vad和Vs)和三种稳定缺陷在1T相中(也就是Sad,Svac和Vad)。此外,Svac,Vad、和Vs结构在2H相中和Vad结构在1T相中的形成可以提尚基面的HER行为,这就意味着VS_2纳米片合成物在V丰富的情况下促进了高HER性能的获取。在原始的或者有缺陷的VS_2结构上的HER行为可以通过一个Fermi-abundance模型很好的理解。这种模型也适合来描述广泛的电催化HER系统。我们的工作提供了单层VS_2上HER行为的深入研究以及在过渡金属二硫化物中合成高效电催化剂的指导方法。
文内图片：

图片说明：图３．２邋（ａ）邋Ｉｎ化结构中晶格常数和能量最化值么间的关系逡逑
[Abstract]:In this paper, a portable infrared detector using new material is proposed, which is composed of four modules. The infrared detection module uses the InSb infrared detector, the data storage and calling module uses the ferroelectric memory based on the ABi _ 2Nb _ 2O _ 9 (A = Ba, Pb, Sr, Ca), the data processing and analysis module uses the graphene high-performance processor which is also in the theoretical demonstration, The life module uses the VS _ 2 substrate as the hydrogen evolution reaction hydrogen battery of the catalyst. Based on the theory, density functional theory, and the first principle method based on it, the four new materials of the four modules are analyzed through the process of constant processing, as follows:1. For InSb (110) surface, we used the first principle to calculate the oxygen and sulfur atoms on the In atom and the Sb atom by the VASP software. The results of the comparison show that the system property after the surface sulfur adsorption of InSb (110) is more stable than that of oxygen adsorption, which also explains why the surface of InSb is to be vulcanized. The structure, electronic properties, chemical bonds and spontaneous polarization of ABi _ 2Nb _ 2O _ 9 (A = Ba, Pb, Sr, Ca) systems are studied by using the first principle of density functional theory. In which the analysis of the chemical bonds combines the molecular (AIM) theory in the atom of the bader. The purpose of this paper is to clarify the ferroelectric origin of the ABi _ 2Nb _ 2O _ 9 ferroelectric, and to understand the change trend of the electron structure and the polarization property of these materials with the A-bit ion. 2. The polarization of SBN is calculated by modern polarization theory, and the polarization of BBN, PBN and CBN is predicted by a theory. We have investigated the structural defects of the graphene that have been reported to date. We will discuss the formation of these defects and their impact on the properties of the graphene. In order for the following discussion to be simple and clear, although there may be a few kinds of lattice defects in nature, we only discuss the simplest ones. We will pay particular attention to the defect of a single-layer graphene, since the defect types of the double layer and the multi-layer graphene already exist in the graphite, and have been discussed early in advance. At the same time, the state density and the energy band structure after the first principle are analyzed. The two-dimensional VS _ 2 nano-material has been present as an electric catalyst with high efficiency and low cost for the hydrogen evolution reaction (HER). To further improve their performance in the hydrogen evolution reaction, we must understand their catalytic mechanism and their behaviour in various original or defective structures. In this paper, we use the first principle to calculate the structural stability, electron and hydrogen evolution of single-layer VS _ 2 nanosheets with various intrinsic point defects. Compared with the most studied 2H-phase MOS _ 2-based surface, the VS _ 2 base surface of both the 2H-phase and the 1T-phase exhibited excellent catalytic activity. Because of their metal properties. After introducing intrinsic electrical defects on the VS _ 2 substrate, we found that there were four stable defects in the 2H phase (i.e., Sad, Svac, Vad, and Vs) and three stable defects in the 1T phase (i.e., Sad, Svac, and Vad). In addition, the formation of Svac, Vad, and Vs in the 2H phase and the Vad structure in the 1-phase phase can be used to improve the HER behavior of the base surface, which means that the VS _ 2 nanosheet composition facilitates the acquisition of the high-HER performance in the case of V-rich. The HER behavior on the original or defective VS _ 2 structure can be well understood by a Fermi-abundance model. Such a model is also suitable for describing a wide electro-catalytic HER system. Our work provides an in-depth study of the HER behavior on single-layer VS _ 2 and a method of guiding the synthesis of highly efficient electrocatalysts in transition metal disulfides.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN215

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