【作者】 李晶；

【导师】 杨培志；

【作者基本信息】 云南师范大学 ， 工程硕士（专业学位）， 2025， 硕士

【摘要】 在现代电子器件追求高性能背景下,器件尺寸不断减小。由于硅基材料不断接近其理论极限,未来尺寸再减小的空间有限,因此迫切需要厚度薄、性能佳的可替代材料。MoS₂作为过渡金属硫化物中的典型代表,因具有载流子迁移率高、光吸收能力强、带隙可调、比表面积大等优点,在集成电路、电催化析氢、纳米器件等领域具有广阔的应用潜力。基于化学气相沉积（CVD）制备MoS₂的工艺虽较为成熟,但得到的MoS₂晶粒大多是随机取向,存在大量的晶界和缺陷,进而影响器件性能。因此,如何可控制备少层MoS₂纳米片成为亟待解决的问题。基于此,本文探索了高质量随机取向MoS₂及定向MoS₂的CVD法制备,比较了其性能差异,并将其应用于摩擦纳米发电机（TENG）以实现能量收集。主要研究内容及结果如下:（1）采用CVD法制备随机取向MoS₂。探索了不同工艺参数对制备随机取向MoS₂性能的影响,获得了优化的工艺参数:生长时间5 min、载气流速20sccm、钼硫比例为1:60,生长温度为800℃;所制备的随机取向MoS₂纳米片尺寸较大,在衬底上分散性较好,厚度约1-2层,表面均匀性较好;通过延长生长时间可获得厚度约3 nm（4-5层）的随机取向MoS₂薄膜。（2）采用CVD法制备定向MoS₂。研究了不同参数对制备定向MoS₂性能的影响,并获得了优化的生长参数。基于该优化工艺,提出了CVD法一步制备定向MoS₂纳米片的新工艺。与传统制备工艺相比,采用一步法制备的定向MoS₂晶粒,尺寸大至200μm,取向率超过70%,且缩短了制备时间,降低了制备成本。（3）将CVD法制备的随机取向MoS₂及定向MoS₂结合TENG作为电荷传输层,以研究其电学性能。对比了定向MoS₂-TENG及随机取向MoS₂-TENG在同样条件下的性能。结果表明:定向MoS₂-TENG的输出电压为110 V、峰值电流为0.6 mA,累积电荷达800 nC;而随机取向MoS₂-TENG由于晶界等缺陷的存在,输出电压仅为85 V、峰值电流为0.2 mA,累积电荷为600 nC。研究了不同超声功率、超声距离和光伏效应等对器件性能的影响,以及固-液模式、固-液-固模式下器件的输出性能。结果表明:定向MoS₂-TENG在超声波作用下5 s内输出电压达到120 V、峰值电流达到2 mA、转移电荷1200 nC。将随机取向MoS₂及定向MoS₂转移至SiO₂/Si衬底并对比垂直电极模式下两者的输出性能,结果表明:晶界主要影响MoS₂水平方向的电荷传输性能,而对垂直方向电荷传输的影响甚微。更多还原

【Abstract】 In the context of the pursuit of high performance in modern electronic devices,the size of the device is constantly being reduced.As silicon-based materials continue to approach their theoretical limits and there is limited room for further size reduction in the future,there is an urgent need for thin,high performance alternative materials.As one of the representative materials of transition metal sulphides,MoS₂ is widely used in integrated circuits,electrocatalytic hydrogen precipitation,and nanodevices due to its high carrier mobility,strong light absorption,adjustable band gap,and large specific surface area.Although the process of MoS₂ preparation based on chemical vapor deposition（CVD）is relatively mature,the obtained MoS₂ grains are mostly randomly oriented,and there are a lot of grain boundaries and defects,which will affect the performance of the device.Therefore,how to controllably prepare MoS₂ nanosheets with fewer layers has become an urgent problem to be solved.On this basis,this paper explores the preparation of high-quality randomly oriented MoS₂ and aligned MoS₂ by CVD method,compares their performance differences and apply them to triboelectric nano generator（TENG）for energy harvesting.The main research contents and results are as follows.（1）Preparation of randomly oriented MoS₂ by CVD method.The influence of different process parameters on the performance of randomly oriented MoS₂ was explored,and the optimized process parameters were obtained:5 min of generation time,20 sccm of carrier gas flow,1:60 molybdenum-sulfur ratio,and 800°C of generation temperature.The prepared randomly oriented MoS₂ nanosheets were larger in size,better dispersed on the substrate,with a thickness of about 1-2 layers and Random oriented MoS₂ films with a thickness of about 3 nm（4-5 layers）can be obtained by extending the growth time.（2）Preparation of aligned MoS₂ by CVD method.The effect of different parameters of CVD method on the preparation of aligned MoS₂ was investigated and the optimized growth parameters were obtained.Based on the optimized process,a new process of one-step preparation of aligned MoS₂ based onCVD method was proposed.Compared with the traditional preparation process,the aligned MoS₂ grains prepared by the one-step process can reach a size of 200μm and an orientation rate of more than70%while taking into account the shortening of the preparation time and the reduction of the preparation cost.（3）Randomly oriented MoS₂ and aligned MoS₂ prepared by CVD method were combined with TENG as a charge transport layer to study their electrical properties.The device performance of aligned MoS₂-TENG and random oriented MoS₂-TENG under the same conditions is compared.The results show that the aligned MoS₂-TENG can output voltage 110 V,peak current 0.6 mA,and accumulated charge 800 nC,while the randomly oriented MoS₂-TENG can only output voltage 85 V,peak current 0.2 mA,and accumulated charge 600 nC due to the presence of defects such as grain boundaries.The effects of different ultrasonic power,ultrasonic distance,and photovoltaic effect on the device performance,as well as the output performance of the device in solid-liquid mode and solid-liquid-solid mode were also investigated.The aligned MoS₂-TENG was capable of outputting 120 V voltage,2 mA current,and accumulated 1200nC charge within 5 s under ultrasonic waves.Randomly oriented MoS₂ and aligned MoS₂ were transferred to SiO₂/Si substrate and compared the output performance of the two devices in vertical electrode mode.The results show that the grain boundary mainly affects the horizontal charge transport performance of MoS₂,but has little effect on the vertical charge transport.更多还原