Abstract
In this work, we theoretically studied the spin caloritronic properties of 7-width armchair graphene nanoribbons with isolated zigzag edge extension (D-system), cove-to-zigzag edge extensions (D1-system), cove-to-cove edge extensions (D2-system), and zigzag-to-zigzag edge extensions (D3-system), respectively, by combining first-principles calculations with a non-equilibrium Green's function method. The results illustrate that the D-system and D1-system with sublattice imbalance show spin-semiconductor properties and obtain thermally induced pure spin current devoid of charge current due to the symmetric spin-up and spin-down channels around the Fermi level. Additionally, it observes substantial spin-dependent Seebeck coefficients Ssp, approximately −2.5 mV/K for the D-system and −3.0 mV/K for the D1-system, near chemical potential ±0.5 eV. More than that, the D1-system showcases a remarkable spin-dependent thermoelectric figure of merit, ZspT, at room temperature, approximately approaching 8 near the Fermi level. In contrast, the D2-system and D3-system only achieved charge-dependent thermoelectric figure of merit of about 0.5 due to the preservation of sublattice balance. Our findings provide important suggestions for designing spin caloritronic devices with high efficiency.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.