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Functionalization of Transition Metal Dichalcogenides with Metallic Nanoparticles: Implications for Doping and Gas-Sensing
journal contribution
posted on 2015-05-13, 00:00 authored by Deblina Sarkar, Xuejun Xie, Jiahao Kang, Haojun Zhang, Wei Liu, Jose Navarrete, Martin Moskovits, Kaustav BanerjeeTransition
metal dichalcogenides (TMDs), belonging to the class of two-dimensional
(2D) layered materials, have instigated a lot of interest in diverse
application fields due to their unique electrical, mechanical, magnetic,
and optical properties. Tuning the electrical properties of TMDs through
charge transfer or doping is necessary for various optoelectronic
applications. This paper presents the experimental investigation of
the doping effect on TMDs, mainly focusing on molybdenum disulfide
(MoS2), by metallic nanoparticles (NPs), exploring noble
metals such as silver (Ag), palladium (Pd), and platinum (Pt) as well
as the low workfunction metals such as scandium (Sc) and yttrium (Y)
for the first time. The dependence of the doping behavior of MoS2 on the metal workfunction is demonstrated and it is shown
that Pt nanoparticles can lead to as large as 137 V shift in threshold
voltage of a back-gated monolayered MoS2 FET. Variation
of the MoS2 FET transfer curves with the increase in the
dose of NPs as well as the effect of the number of MoS2 layers on the doping characteristics are also discussed for the
first time. Moreover, the doping effect on WSe2 is studied
with the first demonstration of p-type doping using Pt NPs. Apart
from doping, the use of metallic NP functionalized TMDs for gas sensing
application is also demonstrated.