Ünsal, ElifSenger, Ramazan TuğrulSevinçli, Haldun2021-12-022021-12-0220212469-99502469-9969https://doi.org/10.1103/PhysRevB.103.014104https://hdl.handle.net/11147/11801In this work, ab initio calculations based on density functional theory and the Landauer formalism are carried out to investigate ballistic thermoelectric properties of T-HfSe2 nanoribbons (NRs). The zigzag-edged NRs are metallic, and they are not included in this study. The armchair NRs possess two types of edge symmetries depending on the number of atoms present in a row; odd-numbered NRs have mirror symmetry, whereas the even-numbered NRs have glide reflection symmetry. The armchair-edged NRs are dynamically stable and show semiconducting properties with varying band gap values in the infrared and visible regions. Detailed transport analyses show that the n-type Seebeck coefficient and the power factor differ because of the structural symmetry, whereas the p-type thermoelectric coefficients are not significantly influenced. It is shown that the phonon thermal conductance is reduced to a third of its two-dimensional value via nanostructuring. The p-type Seebeck coefficient and the power factor for T-phase HfSe(2 )are enhanced in NRs. We report that the p-type ZT value of HfSe2 NRs at 300 and 800 K are enhanced by factors of 4 and 3, respectively.eninfo:eu-repo/semantics/openAccessNanoribbonsHafnium compoundsAb initio calculationsArticle2-s2.0-8509924965310.1103/PhysRevB.103.014104