硫化钼二维材料的制备、光学性质及其器件性能研究

发布时间：2018-05-20 17:01

本文选题：硫化钼 + CVD　；参考：《深圳大学》2017年硕士论文

【摘要】：硫化钼是一种新兴的二维材料,由于其独特的结构和优异的性能引起了科研学者的广泛关注。硫化钼二维材料由于具有可调控的禁带宽度、良好的光吸收性在光电器件领域有巨大的应用潜力,而二维材料的大规模应用离不开高质量材料的可控生长。本论文首先围绕大尺寸单层硫化钼和大面积多层硫化钼的可控生长这一问题,系统研究了生长条件对二维材料尺寸、厚度和质量的影响,随后在低温条件下进行材料的光致发光性质研究和拉曼光谱研究,最后制备了单层硫化钼场效应晶体管,并通过低温下电学测试,结合低温拉曼光谱研究结果开展硫化钼的载流子输运性质研究。具体研究结果如下:1.探讨化学气相沉积法可控生长大尺寸单层硫化钼和大面积多层硫化钼。研究了生长温度、反应源质量分别对单层硫化钼和多层硫化钼生长的影响,得到了尺寸在50μm以上的单层硫化钼和面积在1 cm×2 cm以上的多层均匀硫化钼。2.探讨单层和多层硫化钼的光致发光性质及拉曼光谱。室温下不同层数硫化钼的光致发光性质研究表明,随着层数的减少,硫化钼的发光增强,并分析了单层硫化钼发光增强的原因;研究了单层硫化钼的低温光致发光变化规律,发现单层硫化钼低温下存在A激子、B激子和A-激子三种激子;研究了单层硫化钼的低温拉曼光谱,发现单层硫化钼薄膜受温度影响很小,晶格结构低温下比较稳定。同时发现单层硫化钼的电子浓度会随着温度升高而增大,且在温度上升过程中,12)模式振动突然变弱或者是22)1模式振动突然变强,这种异常的振动变化将影响单层硫化钼场效应晶体管的载流子输运性质。3.探讨场效应晶体管器件性能以及硫化钼载流子输运性质。发现随着温度升高器件阈值电压降低,表明单层硫化钼中的电子浓度随温度的升高而升高。在温度为300 K时,我们得到单层硫化钼场效应晶体管的迁移率为53 cm2.V-1.s-1是迄今为止报道的没有高介电常数介质层包覆的单层硫化钼场效应晶体管的最高迁移率;通过硫化钼迁移率随温度变化关系分析,当温度下降到220 K以下时,不仅由于界面中的存在的缺陷而引起的带电杂质库仑散射,而且还与S原子在层间的振动对载流子的散射有关。当温度上升到220 K以上时,影响迁移率大小的散射机制以声子散射为主,而且以Mo原子与S原子在面内振动的光学声子散射为主导作用。
[Abstract]:Molybdenum sulfide (MoS) is a new two-dimensional material, which has attracted wide attention due to its unique structure and excellent properties. Because of its adjustable bandgap, molybdenum sulphide has a great potential for application in the field of optoelectronic devices. However, the large scale application of molybdenum sulfide can not be separated from the controllable growth of high quality materials. In this paper, the effects of growth conditions on the size, thickness and quality of two-dimensional molybdenum sulfide were studied systematically, focusing on the controllable growth of monolayer molybdenum sulfide and large area multilayer molybdenum sulfide. Then the photoluminescence properties and Raman spectra of the materials were studied at low temperature. Finally, a monolayer molybdenum sulfide field effect transistor was prepared, and the electronic test was carried out at low temperature. The carrier transport properties of molybdenum sulphide were studied by low temperature Raman spectroscopy. The specific research results are as follows: 1. The controlled growth of molybdenum sulphide monolayer and multilayer molybdenum sulfide in large area by chemical vapor deposition was studied. The effects of growth temperature and reaction source mass on the growth of molybdenum sulfide monolayer and multilayer molybdenum sulphide were studied. The molybdenum vulcanized monolayer with size above 50 渭 m and the area above 1 cm 脳 2 cm were obtained. The photoluminescence properties and Raman spectra of monolayer and multilayer molybdenum sulfide were investigated. The photoluminescence properties of molybdenum sulfide at different layers at room temperature show that the luminescence of molybdenum sulfide increases with the decrease of layer number, and the reasons for the enhancement of molybdenum sulphide monolayer are analyzed, and the variation of low temperature photoluminescence of molybdenum sulfide monolayer is studied. It is found that there are three kinds of excitons A exciton B exciton and a-exciton at low temperature and the low temperature Raman spectra of molybdenum sulphide monolayer are studied. It is found that the single layer molybdenum sulfide film is very little affected by temperature and the lattice structure is relatively stable at low temperature. It is also found that the electron concentration of molybdenum sulfide monolayer increases with the increase of temperature, and the mode vibration suddenly weakens or the 22 ~ (1) mode vibration suddenly weakens during the rise of temperature. This abnormal vibration change will affect the carrier transport properties of monolayer molybdenum sulfide field effect transistors. The properties of FET devices and the transport properties of molybdenum sulfide carriers are discussed. It is found that the electron concentration in molybdenum sulfide monolayer increases with the increase of temperature. At a temperature of 300K, we have obtained that the mobility of molybdenum sulfide field effect transistor is 53 cm2.V-1.s-1, which is the highest mobility of single layer molybdenum sulfide field effect transistor without high dielectric constant. Through the analysis of the relationship between molybdenum sulphide mobility and temperature, when the temperature drops below 220 K, the charged impurity Coulomb scattering is caused not only by the defects in the interface, but also by the Coulomb scattering. It is also related to the scattering of carriers by the vibration of S atoms between layers. When the temperature rises above 220 K, phonon scattering is the dominant scattering mechanism, and the optical phonon scattering of Mo atom and S atom vibrates in the plane is dominant.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN386;TQ136.12

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