期刊
NATURE MATERIALS
卷 12, 期 6, 页码 554-561出版社
NATURE PORTFOLIO
DOI: 10.1038/nmat3633
关键词
-
类别
资金
- Center for Re-Defining Photovoltaic Efficiency Through Molecular-Scale Control, an Energy Frontier Research Center
- US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences [DE-SC0001085]
- EFRC
- Cornell Center for Materials Research, an NSF MRSEC [NSF DMR-1120296]
- National Science Foundation [DGE-0707428]
- Columbia University
- GEM PhD Fellowship
- Center for Functional Nanomaterials at Brookhaven National Lab
- Department of Energy Office of Science Graduate Fellowship Program (DOE SCGF) [DE-AC05-06OR23100]
Recent progress in large-area synthesis of monolayer molybdenum disulphide, a new two-dimensional direct-bandgap semiconductor, is paving the way for applications in atomically thin electronics. Little is known, however, about the microstructure of this material. Here we have refined chemical vapour deposition synthesis to grow highly crystalline islands of monolayer molybdenum disulphide up to 120 mu m in size with optical and electrical properties comparable or superior to exfoliated samples. Using transmission electron microscopy, we correlate lattice orientation, edge morphology and crystallinity with island shape to demonstrate that triangular islands are single crystals. The crystals merge to form faceted tilt and mirror twin boundaries that are stitched together by lines of 8- and 4-membered rings. Density functional theory reveals localized mid-gap states arising from these 8- 4 defects. We find that mirror twin boundaries cause strong photoluminescence quenching whereas tilt boundaries cause strong enhancement. Meanwhile, mirror twin boundaries slightly increase the measured in-plane electrical conductivity, whereas tilt boundaries slightly decrease the conductivity.
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