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Abstract The potential of an environmentally friendly and emerging chalcogenide perovskite CaZrSe3for thermoelectric applications is examined. The orthorhombic phase of CaZrSe3has an optimum band gap (1.35–1.40 eV) for single‐junction photovoltaic applications. The predictions reveal that CaZrSe3possesses an absorption coefficient of ≈4 × 105cm−1at photon energies of 2.5 eV with an early onset of optical absorption (≈0.2 eV) well below the optimum band gap. Seebeck coefficient,S, is inversely proportional to the carrier mobility as the calculated average effective mass for electrons is higher than for holes;p‐type doping enhances the electrical conductivity, σ. The electronic thermal conductivityκeremains low at all temperatures. The upper limit of the thermoelectric figure of merit (ZTe) attains ≈1.0 when doped at specific chemical potentials, while a high Seebeck coefficient contributes to the ZTe = 1.95 at 50 K forp‐type doping with 1018cm−3carrier concentration, demonstrating high thermoelectric efficiency.
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Examining the electron transport in chalcogenide perovskite BaZrS 3
Orthorhombic BaZrS 3 is a potential optoelectronic material with prospective applications in photovoltaic and thermoelectric devices. While efforts exist on understanding the effects of elemental substitution and material stability, fundamental knowledge on the electronic transport properties are sparse. We employ first principles calculations to examine the electronic band structure and optical band gap and interrogate the effect of electron transport on electrical and thermal conductivities, and Seebeck coefficient, as a function of temperature and chemical potential. Our results reveal that BaZrS 3 has a band gap of 1.79 eV in proximity of the optimal 1.35 eV recommended for single junction photovoltaics. An absorption coefficient of 3 × 10 5 cm −1 at photon energies of 3 eV is coupled with an early onset to optical absorption at 0.5 eV, significantly below the optical band gap. The carrier effective mass being lower for electrons than holes, we find the Seebeck coefficient to be higher for holes than electrons. A notable (≈1.0 at 300 K) upper limit to the thermoelectric figure of merit, obtained due to high Seebeck coefficient (3000 μV K −1 ) and ultra-low electron thermal conductivity, builds promise for BaZrS 3 as a thermoelectric.
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- PAR ID:
- 10279166
- Date Published:
- Journal Name:
- Journal of Materials Chemistry C
- Volume:
- 9
- Issue:
- 11
- ISSN:
- 2050-7526
- Page Range / eLocation ID:
- 3892 to 3900
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d1tc00374g
