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This content will become publicly available on October 3, 2018

Title: Strong Photothermoelectric Response and Contact Reactivity of the Dirac Semimetal ZrTe 5

The family of three-dimensional topological insulators opens new avenues to discover novel photophysics and to develop novel types of photodetectors. ZrTe 5 has been shown to be a Dirac semimetal possessing unique topological, electronic, and optical properties. Here, we present spatially resolved photocurrent measurements on devices made of nanoplatelets of ZrTe 5, demonstrating the photothermoelectric origin of the photoresponse. Because of the high electrical conductivity and good Seebeck coefficient, we obtain noise-equivalent powers as low as 42 pW/Hz 1/2, at room temperature for visible light illumination, at zero bias. We also show that these devices suffer from significant ambient reactivity, such as the formation of a Te-rich surface region driven by Zr oxidation as well as severe reactions with the metal contacts. This reactivity results in significant stresses in the devices, leading to unusual geometries that are useful for gaining insight into the photocurrent mechanisms. Lastly, our results indicate that both the large photothermoelectric response and reactivity must be considered when designing or interpreting photocurrent measurements in these systems.
Authors:
ORCiD logo [1] ;  [2] ;  [1] ;  [1] ;  [1] ; ORCiD logo [1] ;  [2]
  1. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Report Number(s):
SAND-2017-11576J
Journal ID: ISSN 1944-8244; 658160
Grant/Contract Number:
AC04-94AL85000
Type:
Accepted Manuscript
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 9; Journal Issue: 42; Journal ID: ISSN 1944-8244
Publisher:
American Chemical Society (ACS)
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Dirac semimetal; photocurrent; reactivity; thermoelectric; topological insulator
OSTI Identifier:
1406373