论文标题
使用氟化双层石墨烯屏障在二维材料中的费米水平
Fermi Level Depinning in Two-Dimensional Materials Using a Fluorinated Bilayer Graphene Barrier
论文作者
论文摘要
强的费米水平固定（FLP） - 通常归因于界面接触处金属诱导的间隙状态 - 严重降低了连接处的Schottky屏障高度的可调性，并限制了2D材料在电子和光电上的应用。在这里，我们表明氟化双层石墨烯（FBLG）可用作有效防止在金属/2D材料界面处的FLP的屏障。可以通过短曝光（1-3分钟）对SF6血浆产生FLBG，该血浆仅氟化具有共价C-F键的双层石墨烯的顶层，而底层则保持固有，从而导致带隙开口约为75 MEV。在金属触点和一层MOS2之间插入FBLG，可大大降低Schottky屏障高度的低功能金属（分别为Ti和Cr的313和260 MeV），而高工作功能的一项增加（PD的160 MEV），对应于改进的插针。我们的结果提供了一种直接的方法来生成原子上薄的介电特性，不仅用于将金属/过渡金属二甲元素（TMD）接口的费米水平降低，还用于解决电子和光电方面的许多其他问题
Strong Fermi level pinning (FLP) - often attributed to metal-induced gap states at the interfacial contacts - severely reduces the tunability of the Schottky barrier height of the junction and limits applications of the 2D materials in electronics and optoelectronics. Here, we show that fluorinated bilayer graphene (FBLG) can be used as a barrier to effectively prevent FLP at metal/2D materials interfaces. FLBG can be produced via short exposure (1-3 min) to SF6 plasma that fluorinates only the top layer of a bilayer graphene with covalent C-F bonding, while the bottom layer remains intrinsic, resulting in a band gap opening of about 75 meV. Inserting FBLG between the metallic contacts and a layer of MoS2 reduces the Schottky barrier height dramatically for the low-work function metals (313 and 260 meV for Ti and Cr, respectively) while it increases for the high-work function one ( 160 meV for Pd), corresponding to an improved pinning factor. Our results provide a straightforward method to generate atomically thin dielectrics with applications not only for depinning the Fermi level at metal/transition metal dichalcogenide (TMD) interfaces but also for solving many other problems in electronics and optoelectronics
