Please use this identifier to cite or link to this item:
|Title:||Evolution of electronic structure in atomically thin sheets of ws 2 and wse2||Authors:||Zhao, W.
|Issue Date:||22-Jan-2013||Citation:||Zhao, W., Ghorannevis, Z., Chu, L., Toh, M., Kloc, C., Tan, P.-H., Eda, G. (2013-01-22). Evolution of electronic structure in atomically thin sheets of ws 2 and wse2. ACS Nano 7 (1) : 791-797. ScholarBank@NUS Repository. https://doi.org/10.1021/nn305275h||Abstract:||Geometrical confinement effect in exfoliated sheets of layered materials leads to significant evolution of energy dispersion in mono- to few-layer thickness regime. Molybdenum disulfide (MoS2) was recently found to exhibit indirect-to-direct gap transition when the thickness is reduced to a single monolayer. Emerging photoluminescence (PL) from monolayer MoS2 opens up opportunities for a range of novel optoelectronic applications of the material. Here we report differential reflectance and PL spectra of mono- to few-layer WS2 and WSe2 that indicate that the band structure of these materials undergoes similar indirect-to-direct gap transition when thinned to a single monolayer. The transition is evidenced by distinctly enhanced PL peak centered at 630 and 750 nm in monolayer WS2 and WSe2, respectively. Few-layer flakes are found to exhibit comparatively strong indirect gap emission along with direct gap hot electron emission, suggesting high quality of synthetic crystals prepared by a chemical vapor transport method. Fine absorption and emission features and their thickness dependence suggest a strong effect of Se p-orbitals on the d electron band structure as well as interlayer coupling in WSe2. © 2012 American Chemical Society.||Source Title:||ACS Nano||URI:||http://scholarbank.nus.edu.sg/handle/10635/96532||ISSN:||19360851||DOI:||10.1021/nn305275h|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Mar 3, 2021
WEB OF SCIENCETM
checked on Feb 23, 2021
checked on Feb 28, 2021
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.