npj 2D Materials and Applications (May 2023)

Single-material MoS2 thermoelectric junction enabled by substrate engineering

  • Mohammadali Razeghi,
  • Jean Spiece,
  • Oğuzhan Oğuz,
  • Doruk Pehlivanoğlu,
  • Yubin Huang,
  • Ali Sheraz,
  • Uğur Başçı,
  • Phillip S. Dobson,
  • Jonathan M. R. Weaver,
  • Pascal Gehring,
  • T. Serkan Kasırga

DOI
https://doi.org/10.1038/s41699-023-00406-z
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 6

Abstract

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Abstract To realize a thermoelectric power generator, typically, a junction between two materials with different Seebeck coefficients needs to be fabricated. Such differences in Seebeck coefficients can be induced by doping, which renders it difficult when working with two-dimensional (2d) materials. However, doping is not the only way to modulate the Seebeck coefficient of a 2d material. Substrate-altered electron–phonon scattering mechanisms can also be used to this end. Here, we employ the substrate effects to form a thermoelectric junction in ultrathin, few-layer MoS2 films. We investigated the junctions with a combination of scanning photocurrent microscopy and scanning thermal microscopy. This allows us to reveal that thermoelectric junctions form across the substrate-engineered parts. We attribute this to a gating effect induced by interfacial charges in combination with alterations in the electron–phonon scattering mechanisms. This work demonstrates that substrate engineering is a promising strategy for developing future compact thin-film thermoelectric power generators.