Scanning tunneling microscopy/spectroscopy on MoS₂ embedded nanowire formed in CVD-grown Mo_{1− x} W _x S₂ alloy

Abstract

MoS2 embedded nanowires formed in a transition-metal dichalcogenide (TMDC) layered semiconductor of Mo1−xWxS2 alloy grown by chemical vapor deposition (CVD) on graphite were observed for the first time. Three nanowires radiated outward from the center of each triangular Mo1−xWxS2 island to its three corners, suggesting that they were formed during the growth process. The bandgap energy in the wires was 2.38 eV, 0.03 eV narrower than the average bandgap energy in the region surrounding the nanowire. The observed results suggest the possibility of designing embedded nanostructures in a TMDC by controlling the growth conditions, which should lead to further advances in TMDC materials for the development of new types of devices.

High‐Resolution Electrochemical Mapping of the Hydrogen Evolution Reaction on Transition‐Metal Dichalcogenide Nanosheets

“…Thecurrent-overpotential SECCM movie visualized position dependent HER catalytic activity clearly (Supporting Information, Movie S1). These results indicate that the edge region of the 1H-MoS 2 nanosheets show low overpotential but the Tafel slope did not show ar emarkable difference between edge and terrace region for HER catalysis.T he current image shows at hree highly active lines contrast at the center, which may correspond to grain boundaries or nanowires in the chemical vapor deposition grown 1H-MoS 2 nanosheets, [26] further to the highly active edges (shown by the white arrow in the Supporting Information, Figure S5).…”

Resonant enhancement of band-to-band tunneling in in-plane MoS2/WS2heterojunctions

“…Transition metal dichalcogenides (TMDCs) such as MoS 2 and WS 2 have been attracting much attention for use in electronic nanodevices. [1][2][3][4][5] Recently, in-plane and vertical TMDC heterojunctions have been fabricated, [6][7][8][9] which provide an efficient means of studying and optimizing electrical properties for future device applications. TMDC heterojunctions are especially attractive for use in a channel material of tunnel field-effect transistors (TFETs) [10][11][12][13] because of their superior on-current, excellent gate control and the absence of dangling bonds.…”

Development of laser-combined scanning multiprobe spectroscopy and application to analysis of WSe2/MoSe2 in-plane heterostructure

“…To advance such study, the in-depth understanding and control of local electronic structures and their dynamics in microscopic structures are essential. 3) For such purposes, for example, scanning tunneling microscopy (STM) has been used to evaluate the band structure, [4][5][6] and by forming metal electrodes using techniques such as lithography, time-resolved photocurrent measurement 7) which is an application of the optical pump-probe (OPP) method 8) has been used to observe ultrafast carrier dynamics. In the case of small device structures such as a microscopic TMDC island formed on a insulative material, wired electrodes can be prepared to enable conductive measurement, which, however, requires physical and chemical treatments of samples.…”