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Spatial Mapping of Hot‐Spots at Lateral Heterogeneities in Monolayer Transition Metal Dichalcogenides
Author(s) -
Yasaei Poya,
Murthy Akshay A.,
Xu Yaobin,
dos Reis Roberto,
Shekhawat Gajendra S.,
Dravid Vinayak P.
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201808244
Subject(s) - materials science , heterojunction , monolayer , nanoscopic scale , optoelectronics , grain boundary , scanning thermal microscopy , nanotechnology , hot spot (computer programming) , scanning transmission electron microscopy , transition metal , transmission electron microscopy , microstructure , composite material , chemistry , biochemistry , catalysis , computer science , operating system
Lateral heterogeneities in atomically thin 2D materials such as in‐plane heterojunctions and grain boundaries (GBs) provide an extrinsic knob for manipulating the properties of nano‐ and optoelectronic devices and harvesting novel functionalities. However, these heterogeneities have the potential to adversely affect the performance and reliability of the 2D devices through the formation of nanoscopic hot‐spots. In this report, scanning thermal microscopy (SThM) is utilized to map the spatial distribution of the temperature rise within monolayer transition metal dichalcogenide (TMD) devices upon dissipating a high electrical power through a lateral interface. The results directly demonstrate that lateral heterojunctions between MoS 2 and WS 2 do not largely impact the distribution of heat dissipation, while GBs of MoS 2 appreciably localize heating in the device. High‐resolution scanning transmission electron microscopy reveals that the atomic structure is nearly flawless around heterojunctions but can be quite defective near GBs. The results suggest that the interfacial atomic structure plays a crucial role in enabling uniform charge transport without inducing localized heating. Establishing such structure–property‐processing correlation provides a better understanding of lateral heterogeneities in 2D TMD systems which is crucial in the design of future all‐2D electronic circuitry with enhanced functionalities, lifetime, and performance.