类石墨烯二维光电材料的可控制备及其性能研究

发布时间：2018-02-02 15:48

本文关键词： 过渡金属二硫化物热蒸发法二维纳米结构拓扑绝缘体光电性能　出处：《湘潭大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着石墨烯的发现以及迅速发展,类石墨烯材料逐渐被越来越多的人研究和关注。其中过渡金属二硫化物以其可调带隙结构以及优异的光电性能,特别是在半导体领域中的高的载流子迁移率以及大的开关电流比,使得这类材料逐渐成为一种热门的研究材料。而拓扑绝缘体,它的体态是绝缘的,表面态却呈现出金属性,这源于它较强的自旋轨道耦合作用。拓扑绝缘体的探究和发展将会推动计算机领域的迅速发展。本文对过渡金属二硫化物和拓扑绝缘体纳米结构的制备、表征进行了系统研究,探索了过渡金属二硫化物的光电性能和拓扑绝缘体的光响应特性,并对获得的实验结果进行了系统分析。主要内容如下:1.采用热蒸发法在不同基底(二氧化硅和蓝宝石)上成功地制备出过渡金属二硫化物(WS2、WSe2)的纳米片和大尺寸纳米薄膜结构。实验结果表明,过渡金属二硫化物在蓝宝石基底上更容易获得优异的纳米结构,这跟蓝宝石基底在实验过程中形成的结构有关。实验得到的纳米结构的尺寸非常大,达到了微米甚至是厘米级别。同时我们对其生长演化机制也进行了探究。采用开尔文力显微镜、拉曼光谱、扫描电子显微镜等表征手段对制备的样品进行了系统的研究。过渡金属二硫化物作为新型半导体光电材料,探究其光电性能具有非常重要的现实意义。同时我们对得到的样品的表面电势分布以及光致发光性能进行了研究,并尝试解释其产生相应现象的原因。2.首先采用热蒸发法成功制备出测试需要的拓扑绝缘体纳米材料。然后利用自制三电极光电测试系统探究其光响应性能。通过对比Bi2Se3块体和Bi2Se3纳米片在模拟太阳光下的光响应数据,确定Bi2Se3纳米片具有更好的导电性、光响应循环稳定性以及大的电流差。利用单色光源对Bi2Se3纳米片的光响应性能进行光响应的重复实验。发现其在光源波长为455 nm时,具有最高的灵敏性,此时暗电流比在模拟太阳光下的暗电流低。在波长为655 nm的光源下时,其灵敏性高于模拟太阳光条件下的灵敏性,而低于波长455 nm时的灵敏性,但是此时的暗电流在测试的数据中最小。同时,我们也测试了Bi2Te3的光响应特性。实验结果表明,拓扑绝缘体纳米结构在光电传感器领域具有一定的潜在应用价值。
[Abstract]:With the discovery and rapid development of graphene, graphene like materials have been studied and paid more and more attention. Among them, transition metal disulfide is characterized by its tunable band gap structure and excellent optoelectronic properties. Especially in the field of semiconductor, the high carrier mobility and the large switching current ratio make these materials become a hot research material, and the topology insulator, its body state is insulating. The surface state, however, presents a gold attribute. This is due to its strong spin-orbit coupling. The exploration and development of topological insulators will promote the rapid development of the computer field. In this paper, transition metal disulfide and topological insulator nanostructures are prepared. The photoelectric properties of transition metal disulfide and the photoresponse characteristics of topological insulators were investigated. The experimental results are analyzed systematically. The main contents are as follows: 1. The transition metal disulfide (TMS) WS2 was successfully prepared on different substrates (silicon dioxide and sapphire) by thermal evaporation method. The experimental results show that transition metal disulfide is easier to obtain excellent nanostructures on sapphire substrates. This is related to the structure of the sapphire substrate formed during the experiment. The size of the nanostructures obtained is very large. At the same time, we also studied the mechanism of its growth and evolution. Using Kelvin force microscope, Raman spectroscopy. The transition metal disulfide (TME) as a new type of semiconductor optoelectronic material was systematically studied by means of scanning electron microscope (SEM). It is of great practical significance to explore the photoelectric properties of the samples. At the same time, we have studied the surface potential distribution and photoluminescence properties of the samples. First, the topological insulator nanomaterials were successfully prepared by thermal evaporation method, and then the photoresponse properties of these materials were investigated by using a self-made three-electrode photoelectric test system. The photoresponse data of Bi2Se3 block and Bi2Se3 nanochip under simulated solar light were compared. It is confirmed that Bi2Se3 nanoparticles have better electrical conductivity. Optical response cycle stability and large current difference. The photoresponse of Bi2Se3 nanoparticles was repeated with monochromatic light source. It was found that the light source wavelength was 455nm. It has the highest sensitivity, the dark current is lower than the dark current in the simulated solar light, and the sensitivity is higher at the wavelength of 655 nm than that under the simulated solar light. The sensitivity is lower than the wavelength of 455nm, but the dark current is the smallest in the measured data. At the same time, we have also tested the light response characteristics of Bi2Te3. The experimental results show that. Topological insulator nanostructures have potential application value in the field of optoelectronic sensors.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.11

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