skip to main content

DOE PAGESDOE PAGES

Title: Negative Differential Conductance & Hot-Carrier Avalanching in Monolayer WS2 FETs

The high field phenomena of inter-valley transfer and avalanching breakdown have long been exploited in devices based on conventional semiconductors. In this Article, we demonstrate the manifestation of these effects in atomically-thin WS 2 field-effect transistors. The negative differential conductance exhibits all of the features familiar from discussions of this phenomenon in bulk semiconductors, including hysteresis in the transistor characteristics and increased noise that is indicative of travelling high-field domains. It is also found to be sensitive to thermal annealing, a result that we attribute to the influence of strain on the energy separation of the different valleys involved in hot-electron transfer. This idea is supported by the results of ensemble Monte Carlo simulations, which highlight the sensitivity of the negative differential conductance to the equilibrium populations of the different valleys. At high drain currents (>10 μA/μm) avalanching breakdown is also observed, and is attributed to trap-assisted inverse Auger scattering. This mechanism is not normally relevant in conventional semiconductors, but is possible in WS 2 due to the narrow width of its energy bands. The various results presented here suggest that WS 2 exhibits strong potential for use in hot-electron devices, including compact high-frequency sources and photonic detectors.
Authors:
 [1] ; ORCiD logo [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [1] ;  [1] ;  [5] ;  [6] ;  [5] ;  [7] ;  [8] ;  [8] ; ORCiD logo [8] ;  [8] ;  [9] ; ORCiD logo [1]
  1. University at Buffalo, the State University of New York, Buffalo, NY (United States). Department of Electrical Engineering
  2. University at Buffalo, the State University of New York, Buffalo, NY (United States). Department of Physics
  3. King Mongkut’ s Institute of Technology Ladkrabang, Bangkok (Thailand)
  4. Institute of Microelectronics of Chinese Academy of Sciences, Beijing (China). High-Frequency High-Voltage Device and Integrated Circuits Center
  5. Pennsylvania State Univ., University Park, PA (United States). Department of Physics and Center for 2-Dimensional and Layered Materials
  6. Pennsylvania State Univ., University Park, PA (United States). Department of Materials Science and Engineering and Materials Research Institute
  7. Pennsylvania State Univ., University Park, PA (United States). Department of Physics and Center for 2-Dimensional and Layered Materials, Department of Materials Science and Engineering and Materials Research Institute and Department of Chemistry and Materials Research Institute
  8. Rice Univ., Houston, TX (United States). Department of Materials Science and Nano Engineering
  9. Arizona State Univ., Tempe, AZ (United States). School of Electrical, Computer, and Energy Engineering
Publication Date:
Grant/Contract Number:
FG02-04ER46180
Type:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 2045-2322
Publisher:
Nature Publishing Group
Research Org:
State Univ. of New York (SUNY), Plattsburgh, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Electronic devices; Two-dimensional materials
OSTI Identifier:
1429880