Au(111)表面WS_(2)成核控制的理论研究  

Theoretical study on the nucleation control of WS_(2) on Au(111)surfaces

作　　者：胡艺山 袁清红 Hu Yi-Shan;Yuan Qing-Hong(State Key Laboratory of Precision Spectroscopy School of Physics and Electronic Science,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学,精密光谱科学与技术国家重点实验室,上海200241

出　　处：《物理学报》2024年第13期111-120,共10页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2021YFA1200801);国家自然科学基金(批准号:22173031)资助的课题。

摘　　要：二维二硫化钨(WS_(2))作为一种具有层依赖的电子和光电特性的半导体材料,在光电器件领域展现出极具潜力的应用前景.当前,晶圆级单层WS_(2)薄膜的制备是推动其在先进晶体管和集成电路中应用的关键挑战.化学气相沉积(CVD)能够实现大尺寸、高质量的单层WS_(2)薄膜合成,但其生长过程的复杂性导致了WS_(2)生长效率低,质量参差不齐.为指导实验上减少WS_(2)晶界,提高薄膜质量以增强其电子性能和机械稳定性,本文基于第一性原理的理论计算,深入探讨了WS_(2)在CVD生长过程中的成核机制.通过引入化学势这一变量,分析了不同实验条件下WS_(2)的生长能量曲线,发现调整前驱体钨源和硫源的温度或压强能有效控制WS_(2)的成核速率.特别是当钨源温度为1250 K时,成核速率达到最大,而提高硫源温度或降低硫源压强则能降低成核速率,从而提高单层WS_(2)的结晶度和均匀性.这些理论计算结果为实验中根据需求精确调整成核速率提供了坚实的理论依据,并为如何通过优化实验参数来提高单层WS_(2)薄膜的结晶度和均匀性提供了理论指导,有望推动WS_(2)材料在各类高性能电子器件中的应用发展,对未来材料科学和工业应用具有重要意义.Two-dimensional tungsten disulfide(WS_(2)),as a semiconductor material with unique layer-dependent electronic and optoelectronic characteristics,demonstrates a promising application prospect in the field of optoelectronic devices.The fabrication of wafer-scale monolayer WS_(2)films is currently a critical challenge that propels their application in advanced transistors and integrated circuits.Chemical vapor deposition(CVD)is a feasible technique for fabricating large-area,high-quality monolayer WS_(2)films,yet the complexity of its growth process results in low growth efficiency and inconsistent film quality of WS_(2).In order to guide experimental efforts to diminish grain boundaries in WS_(2),thereby improving film quality to enhance electronic performance and mechanical stability,this study investigates the nucleation mechanisms of WS_(2)during CVD growth through first-principles theoretical calculations.By considering chemical potential as a crucial variable,we analyze the growth energy curves of WS_(2)under diverse experimental conditions.Our findings demonstrate that modulating the temperature or pressure of the tungsten and sulfur precursors can decisively influence the nucleation rate of WS_(2).Notably,the nucleation rate reaches a peak at a tungsten source temperature of 1250 K,while an increase in sulfur source temperature or a decrease in pressure can suppress the nucleation rate,thereby enhancing the crystallinity and uniformity of monolayer WS_(2).These insights not only furnish a robust theoretical foundation for experimentally fine-tuning the nucleation rate as needed but also provide strategic guidance for optimizing experimental parameters to refine the crystallinity and uniformity of monolayer WS_(2)films.Such advancements are expected to accelerate the deployment of WS_(2)materials in a range of highperformance electronic devices,marking a significant stride in the field of materials science and industrial applications.

关 键 词：第一性原理计算 生长机制 化学气相沉积 二维二硫化钨 

分 类 号：O469[理学—凝聚态物理]