Intrinsic Modulation Doping Enhances the Thermoelectric Performance of Monolayer Gagete
Published In
Acs Applied Energy Materials
Document Type
Citation
Publication Date
11-21-2023
Abstract
Modulation doping is a well-known approach for improving the efficiency of bulk thermoelectrics, yet its application to 2D materials has remained elusive. Our thorough first-principles calculations reveal a unique intrinsic modulation doping in monolayer GaGeTe that synergistically raises its electrical transport coefficients while dwarfing its lattice heat transport, resulting in a high thermoelectric figure of merit, zT. Herein, we envision 2D GaGeTe as a chair-like germanene monolayer shrouded by two GaTe layers. The germanene layer donates electrons to the outer GaTe, creating a spatial separation between the electron-donation center and charge transport channels, a feature that suppresses free carrier scattering. Our accurate electron–phonon calculations explain that electrical transport in GaGeTe results from the metallic nature of germanene combined with the Mexican-hat shape of the GaTe valence band. The superior electrical and poor heat transport coefficients turn GaGeTe into a promising p-type thermoelectric monolayer working at moderate carrier concentrations of ≈1013 cm–2. The presented results put forward a distinct design approach for identifying competent thermoelectrics among 2D materials whose frail structures cannot tolerate heavy doping.
Rights
Copyright © 2023 American Chemical Society
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DOI
10.1021/acsaem.3c02062
Persistent Identifier
https://archives.pdx.edu/ds/psu/41334
Citation Details
Rafiee Diznab, M., Xia, Y., & Naghavi, S. S. (2023). Intrinsic Modulation Doping Enhances the Thermoelectric Performance of Monolayer GaGeTe. ACS Applied Energy Materials, 6(23), 11915–11923.