Cr、Ti掺杂Cu/石墨烯界面结合性能的第一性原理预测

摘要

基于密度泛函理论,对过渡金属Cr、Ti掺杂的Cu/石墨烯界面结合性能进行第一性原理预测,构建并对比一系列不同Cu/石墨烯界面的三明治和表面模型.计算结果表明,界面位相关系对界面结合强度影响不大.两种界面模型的计算结果均显示top-fcc配位模型是最稳定的界面结构,并具有较低的界面结合能.Cr掺杂倾向于偏析到界面上取代Cu,而Ti惨杂倾向于占据界面处的填隙位.虽然这两种元素的偏析趋势都较弱,其偏析可以显著提高界面的结合性能,从而强化界面.%We presented a density functional theory study on doping effects of transition metals (Cr and Ti) on the Cu/graphene interface adhesion. Various undoped Cu/graphene interface structures were constructed using both the sandwich and the surface models. Energetics calculations showed that the interface binding strength only weakly depends on interface coordination. Both interface models predicted the top-fcc coordination type as the most energy-favored, with a low binding energy value. Segregated Cr prefers to substituting for Cu, while Ti occupies a hollow site at the interface. Although the segregation tendencies are both very weak, once present on the interface, both dopants can greatly increase the interface binding energy and improve the adhesion.