TMD/石墨烯的叠层结构稳定性及其光电特性的应变调控研究

项目名称： TMD/石墨烯的叠层结构稳定性及其光电特性的应变调控研究

项目编号： No.51471130

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 马飞

作者单位： 西安交通大学

项目金额： 85万元

中文摘要： 石墨烯的成功分离和新奇物性的发现极大推动了人们对二维晶体的研究热潮。超过10%的弹性应变极限是探索和利用其力/光和力/电耦合特性的先天特有条件。就此已有研究工作涉足，但多围绕单组元单片层结构来开展。具有层间耦合作用的异质叠层体系在外加应力作用下的行为远比单片层体系复杂，且不能进行简单叠加或推演。本项目拟以典型过渡族金属硫系化合物（TMDs）与石墨烯所形成的异质叠层结构为例，结合理论模拟计算和实验表征分析，考察并明确在层间内应变协调和外应力干预下的结构稳态化及其与光电功能特性稳定化的关系；研究和探讨界面电荷转移可能引起的电子态、带边位置及狄拉克能级的变化，建立TMD/石墨烯异质结属性与外加应力之间的关联关系；揭示在层间耦合与应变效应交互作用下TMD/石墨烯叠层结构的光电特性增强或调控的物理机制，为新型高效光伏、光催化、光探测器件的探索及其性能的应力/应变调控提供新思路。

中文关键词： 二维晶体；叠层结构；应变效应；光电特性

英文摘要： The successful fabrication of graphene through mechanical or chemical exfoliation and the findings of its novel properties attracted more and more research interests in two-dimensional (2D) crystals from the communities of physics, chemistry and material science all over the world. In fact, any bulk materials with layered structures and bonded through van der Waarls forces could be seperated into graphene-like 2D crystals. The typical one is transition metal dichalcogenides (TMDs). The elastic strain they can sustain exceeds 10%, much higher than those of the counterpart bulks. This provides the congenital condition to explore and utilize the coupling effects of mechanical/optical as well as mechanical/electronic properties of 2D crystals. Some research works have been conducted in this field, but mainly focused on the single-component systems. As for the hetergeneously layered structure with interlayer coupling, the behaviors under stress are extremely more complicated than those of the single-layer ones and, it can not be obtained through simple superposition or extrapolation. In this proposal, taking typical TMD/graphene heterogeneous structures as examples, we will systematically study the stress/strain effects on the structural stablity and the optical properties from both theoretical and experimental aspects. The stable configurations as well as the stable photoelectric properties under internal strain coordination and external stress intervention will be explored at first. Accordingly, we would like to analyze and uncover the changes in electronic states, band edges and the Dirac energy as a result of electron transfer across the heterogeneous interface, establish the relationship between the heterojunction nature and the external stress. Based on this, it is expected to illustrate the physical mechanisms for the enhanced photoelectric properties under both the interlayer coupling and strain effect. This might present us new ideas to develop high-performance photovoltaic cells, photocatalysis and photodetector devices and to engineer the physical properties by mechanical straining.

英文关键词： two-dimensional crystal;stacked structure;strain effect;photoelectric properties