Spatial Mapping of Hot-Spots at Lateral Heterogeneities in Monolayer Transition Metal Dichalcogenides

Poya Yasaei, Akshay A. Murthy, Yaobin Xu, Roberto dos Reis, Gajendra S. Shekhawat*, Vinayak P. Dravid

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

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 MoS2 and WS2 do not largely impact the distribution of heat dissipation, while GBs of MoS2 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.

Original languageEnglish (US)
Article number1808244
JournalAdvanced Materials
Volume31
Issue number24
DOIs
StatePublished - Jun 13 2019

Funding

P.Y. and A.A.M. contributed equally to this work. P.Y., A.A.M., G.S.S., and V.P.D. conceived the idea and designed the experiments. A.A.M. synthesized the materials and fabricated the devices. P.Y. performed the SThM and electrical tests. P.Y. and A.A.M. carried out the characterizations. V.P.D. and G.S.S. supervised the experiments. V.P.D. supervised electron microscopy. Y.X. and R.D.R. performed the TEM and EDS characterizations. All authors contributed to the writing of the manuscript. This material is based upon work supported by the National Science Foundation (DMR-1507810). This work made use of the EPIC, Keck-II, NUFAB and SPID facilities of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1720319) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. This work also made use of the Pritzker Nanofabrication Facility of the Institute for Molecular Engineering at the University of Chicago, which receives support from SHyNE Resource (NSF ECCS-1542205). A.A.M. gratefully acknowledges support from the Ryan Fellowship and the IIN at Northwestern University. P.Y. and A.A.M. contributed equally to this work. P.Y., A.A.M., G.S.S., and V.P.D. conceived the idea and designed the experiments. A.A.M. synthesized the materials and fabricated the devices. P.Y. performed the SThM and electrical tests. P.Y. and A.A.M. carried out the characterizations. V.P.D. and G.S.S. supervised the experiments. V.P.D. supervised electron microscopy. Y.X. and R.D.R. performed the TEM and EDS characterizations. All authors contributed to the writing of the manuscript. This material is based upon work supported by the National Science Foundation (DMR-1507810). This work made use of the EPIC, Keck-II, NUFAB and SPID facilities of Northwestern University's NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1720319) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. This work also made use of the Pritzker Nanofabrication Facility of the Institute for Molecular Engineering at the University of Chicago, which receives support from SHyNE Resource (NSF ECCS-1542205). A.A.M. gratefully acknowledges support from the Ryan Fellowship and the IIN at Northwestern University.

Keywords

  • 2D materials
  • grain boundaries
  • lateral heterostructures
  • scanning thermal microscopy
  • transition metal dichalcogenides

ASJC Scopus subject areas

  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering

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