二维金属与CrCl_(3)接触的界面性质

Interface properties of two-dimensional metal in contact with CrCl_(3)

为了调控金属与CrCl_(3)界面处的势垒,提出二维金属MX_(2)(M=V,Nb;X=S,Se,Te)作为电极与CrCl_(3)形成范德华接触的方法.采用密度泛函理论研究CrCl_(3)/MX_(2)接触界面的电学性质.结果表明:CrCl_(3)/VS_(2)、CrCl_(3)/VSe_(2)和CrCl_(3)/NbTe_(2)形成n型肖特基接触,其n型肖特基势垒值分别为0.49、0.15和0.14 eV;CrCl_(3)/NbS_(2)和CrCl_(3)/NbSe_(2)形成p型肖特基接触,其p型肖特基势垒值分别为0.49和0.65 eV;CrCl_(3)/VTe_(2)形成欧姆接触.CrCl_(3)/MX_(2)界面处可忽略的金属诱导间隙态和较小的界面偶极表明,CrCl_(3)/MX_(2)中存在较弱的费米能级钉扎效应,从而使肖特基势垒高度可以在较大范围可调.因此,通过选择不同功函数的二维金属电极,在CrCl_(3)/MX_(2)接触结构中能够实现接触类型和肖特基势垒高度的调控.研究结果有助于理解不同二维金属电极对CrCl_(3)/MX_(2)接触的势垒调控.

To modulate the potential barrier at the interface between metal and CrCl_(3),a method for forming van der Waals contact with CrCl_(3)using two-dimensional metal MX_(2)(M=V,Nb;X=S,Se,Te)as electrode was proposed.The electrical properties of CrCl_(3)/MX_(2)contact interface were studied using density functional theory.The results show that CrCl_(3)/VS_(2),CrCl_(3)/VSe_(2)and CrCl_(3)/NbTe_(2)form n-type Schottky contacts,the n-type Schottky barrier values are 0.49,0.15 and 0.14 eV,respectively.CrCl_(3)/NbS_(2)and CrCl_(3)/NbSe_(2)form p-type Schottky contacts,the p-type Schottky barrier values are 0.49 and 0.65 eV,respectively.CrCl_(3)/VTe_(2)forms ohmic contacts.The negligible metal induced gap states and small interface dipoles at CrCl_(3)/MX_(2)interface indicate a weak Fermi level pinning effect in CrCl_(3)/MX_(2),which makes the Schottky barrier height adjustable in a large range.Therefore,by selecting two-dimensional metal electrodes with different work functions,the control of contact type and Schottky barrier height can be achieved in CrCl_(3)/MX_(2)contacts.The results is helpful to understand the barrier regulation of CrCl_(3)/MX_(2)contact by different two-dimensional metal electrodes.