论文标题
二维材料的隧道光谱基于通过触点
Tunneling Spectroscopy of Two-Dimensional Materials Based on Via Contacts
论文作者
论文摘要
我们为范德华异质结构引入了一种新颖的平面隧道建筑，基于通过触点，即金属触点嵌入了六角形硝化硼（$ h $ bn）中的整个孔中。我们使用基于VIA的隧道方法研究两种不同的二维（2D）材料的状态的单粒子密度，即NBSE $ _2 $和石墨烯。在NBSE $ _2 $设备中，我们表征了0、1和2层的屏障强度和界面障碍$ h $ bn的层，并研究对隧道接触区域的依赖，降低至$（44 \ pm 14）^2 $ nm $ $^2 $。对于0层$ h $ bn设备，我们演示了从扩散到小型区域限制的点触点的交叉。在石墨烯中，我们表明，减小隧道屏障厚度和面积可以抑制$ H $ bn屏障中的辅助隧道和缺陷，从而抑制效果。这种基于基于的建筑克服了其他平面隧道设计的局限性，并从各种2D材料中产生了高质量的超塑性隧道结构。
We introduce a novel planar tunneling architecture for van der Waals heterostructures based on via contacts, namely metallic contacts embedded into through-holes in hexagonal boron nitride ($h$BN). We use the via-based tunneling method to study the single-particle density of states of two different two-dimensional (2D) materials, NbSe$_2$ and graphene. In NbSe$_2$ devices, we characterize the barrier strength and interface disorder for barrier thicknesses of 0, 1 and 2 layers of $h$BN and study the dependence on tunnel-contact area down to $(44 \pm 14)^2 $ nm$^2$. For 0-layer $h$BN devices, we demonstrate a crossover from diffusive to point contacts in the small-contact-area limit. In graphene, we show that reducing the tunnel barrier thickness and area can suppress effects due to phonon-assisted tunneling and defects in the $h$BN barrier. This via-based architecture overcomes limitations of other planar tunneling designs and produces high-quality, ultra-clean tunneling structures from a variety of 2D materials.
