Tailoring the charge carrier in few layers MoS 2 field-effect transistors by Au metal adsorbate

Abstract

It is an essential to tune the charge carrier concentrations in semiconductor in order to approach high-performance of the electronic and optoelectronic devices. Here, we report the effect of thin layer of gold (Au) metal on few layer (FL) molybdenum disulfide (MoS 2 ) by atomic force microscopy (AFM), Raman spectroscopy and electrical charge transport measurements. The Raman spectra and charge transport measurements show that Au thin layer affect the electronic properties of the FL MoS 2 . After deposition of Au thin layer, the threshold voltages of FL MoS 2 field-effect transistors (FETs) shift towards positive gate voltages, this reveal the p-doping in FL MoS 2 nanosheets. The shift of peak frequencies of the Raman bands are also analyzed after the deposition of Au metal films of different thickness on FL MoS 2 nanosheets. The surface morphology of Au metal on FL MoS 2 is characterized by AFM and shows the smoother and denser film in comparison to Au metal on SiO 2 . © 2017 Elsevier B.V.