Bandgap tunability at single-layer molybdenum disulphide grain boundaries

Yu Li Huang, Yifeng Chen, Wenjing Zhang, Su Ying Quek*, Chang Hsiao Chen, Lain Jong Li, Wei Ting Hsu, Wen-Hao Chang, Yu Jie Zheng, Wei Chen, Andrew T.S. Wee

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

250 Scopus citations

Abstract

Two-dimensional transition metal dichalcogenides have emerged as a new class of semiconductor materials with novel electronic and optical properties of interest to future nanoelectronics technology. Single-layer molybdenum disulphide, which represents a prototype two-dimensional transition metal dichalcogenide, has an electronic bandgap that increases with decreasing layer thickness. Using high-resolution scanning tunnelling microscopy and spectroscopy, we measure the apparent quasiparticle energy gap to be 2.40±0.05 eV for single-layer, 2.10±0.05 eV for bilayer and 1.75±0.05 eV for trilayer molybdenum disulphide, which were directly grown on a graphite substrate by chemical vapour deposition method. More interestingly, we report an unexpected bandgap tunability (as large as 0.85±0.05 eV) with distance from the grain boundary in single-layer molybdenum disulphide, which also depends on the grain misorientation angle. This work opens up new possibilities for flexible electronic and optoelectronic devices with tunable bandgaps that utilize both the control of two-dimensional layer thickness and the grain boundary engineering.

Original languageEnglish
Article number6298
Pages (from-to)1-8
Number of pages8
JournalNature Communications
Volume6
DOIs
StatePublished - 17 Feb 2015

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