Open AccessWS2 and MoS2 thin film gas sensors with high response to NH3 in air at low temperature
Author(s) -
Topias Järvinen,
Gabriela S. Lorite,
Jani Peräntie,
Géza Tóth,
Simo Saarakkala,
Vesa Virtanen,
Krisztián Kordás
Publication year - 2019
Publication title -
nanotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.926
H-Index - 203
eISSN - 1361-6528
pISSN - 0957-4484
DOI - 10.1088/1361-6528/ab2d48
Subject(s) - materials science , adsorption , sputtering , oxide , selectivity , thin film , metal , transition metal , analyte , analytical chemistry (journal) , silicon , nanotechnology , optoelectronics , chemistry , metallurgy , organic chemistry , catalysis
Transition metal dichalcogenides (TMDs) have received immense research interest in particular for their outstanding electrochemical and optoelectrical properties. Lately, chemical gas sensor applications of TMDs have been recognized as well owing to the low operating temperatures of devices, which is a great advantage over conventional metal oxide based sensors. In this work, we elaborate on the gas sensing properties of WS 2 and MoS 2 thin films made by simple and straightforward thermal sulfurization of sputter deposited metal films on silicon chips. The sensor response to H 2 , H 2 S, CO and NH 3 analytes in air at 30 °C has been assessed and both MoS 2 and WS 2 were found to have an excellent selectivity to NH 3 with a particularly high sensitivity of 0.10 ± 0.02 ppm −1 at sub-ppm concentrations in the case of WS 2 . The sensing behavior is explained on the bases of gas adsorption energies as well as carrier (hole) localization induced by the surface adsorbed moieties having reductive nature.