期刊
NANO LETTERS
卷 17, 期 10, 页码 5962-5968出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.nanolett.7b01986
关键词
Transition metal dichalcogenide; scanning tunneling microscopy/spectroscopy; 2D semiconductor; band mapping; ohmic contact; molybdenum disulfide
类别
资金
- National Science Foundation (NSF) Materials Research Science and Engineering Center at Columbia University [DMR 1420634]
- Air Force Office of Scientific Research [FA9550-16-1-0601, FA9550-16-1-0031]
- NSF through the Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM) [DMR-1539918]
- Cornell Center for Materials Research [NSF DMR-1120296]
- Direct For Mathematical & Physical Scien
- Division Of Materials Research [1539918] Funding Source: National Science Foundation
High quality electrical contact to semiconducting transition metal dichalcogenides (TMDCs) such as MoS2 is key to unlocking their unique electronic and optoelectronic properties for fundamental research and device applications. Despite extensive experimental and theoretical efforts reliable ohmic contact to doped TMDCs remains elusive and would benefit from a better understanding of the underlying physics of the metal-TMDC interface. Here we present measurements of the atomic-scale energy band diagram of junctions between various metals and heavily doped monolayer MoS2 using ultrahigh vacuum scanning tunneling microscopy (UHV-STM). Our measurements reveal that the electronic properties of these junctions are dominated by two-dimensional metal-induced gap states (MIGS). These MIGS are characterized by a spatially growing measured gap in the local density of states (L-DOS) of the MoS2 within 2 nm of the metal-semiconductor interface. Their decay lengths extend from a minimum of similar to 0.55 rim near midgap to as long as 2 nm near the band edges and are nearly identical for Au, Pd, and graphite contacts, indicating that it is a universal property of the monolayer semiconductor. Our findings indicate that even in heavily doped semiconductors, the presence of MIGS sets the ultimate limit for electrical contact.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据