File Download

There are no files associated with this item.

  • Find it @ UNIST can give you direct access to the published full text of this article. (UNISTARs only)
Related Researcher

김수현

Kim, Soo-Hyun
Read More

Views & Downloads

Detailed Information

Cited time in webofscience Cited time in scopus
Metadata Downloads

Low-temperature direct synthesis of high quality WS2 thin films by plasma-enhanced atomic layer deposition for energy related applications

Author(s)
Yeo, SeungminNandi, Dip K.Rahul, R.Kim, Tae HyunShong, BonggeunJang, YujinBae, Jong-SeongHan, Jeong WooKim, Soo-HyunKim, Hyungjun
Issued Date
2018-11
DOI
10.1016/j.apsusc.2018.07.210
URI
https://scholarworks.unist.ac.kr/handle/201301/64082
Fulltext
https://www.sciencedirect.com/science/article/pii/S016943321832107X?via%3Dihub
Citation
APPLIED SURFACE SCIENCE, v.459, pp.596 - 605
Abstract
Tungsten disulfide (WS2) thin films are grown on several types of substrates by plasma-enhanced atomic layer deposition (PEALD) technique using tungsten hexacarbonyl [W(CO)(6)] and H2S plasma at a relatively low temperature of 350 degrees C. The method delivers polycrystalline WS2 film with (0 0 2) preferential growth and the high quality films could be successfully grown with as low as 30 ALD cycles (corresponding to similar to 3 nm of thickness). Density functional theory (DFT) calculation results reveal that both adsorption of W(CO)(6) and removal of CO ligand would be facilitated by usage of H2S plasma by generating the different defect sites on the basal plane. The typical self-limiting film growth (growth rate of similar to 0.1 nm/cycle), characteristic of ideal ALD, is clearly observed with both the precursor and reactant pulsing time. X-ray diffractometry (XRD), Raman spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Rutherford backscattering spectrometry (RBS) are performed in details to study the as-grown WS2 film on Si/SiO2 substrate. The analysis results confirm the formation of polycrystalline film, with high purity and well-defined stoichiometry. The as-deposited WS2 films are then explored as an electrode in the field of energy generation as well as energy storage. The films are uniformly and conformally grown on high surface-area 3 dimensional Ni-foam that show excellent activity towards hydrogen evolution reaction (HER). Significantly low overpotential of similar to 280 mV is observed at a high operational current density of 100 mA cm(-2) during HER in acid electrolyte. In addition, the as-grown films on stainless steel substrate also reveal the stable electrochemical performances in Na-ion battery as an anode with reasonably high areal capacity of similar to 44.5 mu Ah cm(-2) at the end of 50 charge-discharge cycles.
Publisher
ELSEVIER
ISSN
0169-4332
Keyword (Author)
Plasma-enhanced atomic layer depositionTungsten hexacarbonylDensity functional theoryTungsten disulfideHydrogen evolution reactionNa-ion battery
Keyword
TUNGSTEN DISULFIDE NANOSHEETSWAFER-SCALEPERFORMANCEANODEGROWTHMOS2ELECTROCATALYSTCRYSTALLINE

qrcode

Items in Repository are protected by copyright, with all rights reserved, unless otherwise indicated.