Thermoelectric properties of layered ternary telluride Nb3SiTe6

Anisotropic photocurrent response at MnBi2Te4-metal interface

“…We can calculate the elevated temperature ∆T due to light absorption to be ∆T ∼ 0.025 K. This corresponds to a PC of 2.25 nA (detailed calculation process is shown in the supplementary note 6). Considering the sample variation of Seebeck coefficient [33,34] and the overestimation of ∆T due to neglecting other thermal relaxation channels such as substrate phonons, the calculated photo-thermoelectric PC is consistent to the measured PC of 0.557 nA in our experiment. Third, the temperature dependence of PC response magnitudes is consistent with photo-thermoelectric origin as Seebeck coefficient decrease with temperature.…”

Dirac Nodal Line in Hourglass Semimetal Nb3SiTe6

“…For cut 2 parallel to normalΓ normalY true̅ [Figure (c)], two parabolic bands opening upwarda small one with its minimum at E ≈ −0.02 eV and another spanning the energy range E = 0 to −0.2 eVare repeatedly observable at the zone centers of multiple Brillouin zones [see Figure (c) from k y = −0.78 to −1.82 Å –1 ]; however, for cut 4 parallel to normalΓ normalX true̅ [Figure (e)], a large, hole-like band centered about the zone center and with its apex at E ≈ −0.02 eV is instead discernible. These two results thus reveal a saddle-like surface in energy-momentum space, with its saddle point at the zone center at E ≈ −0.02 eV, as well as the dominance of hole-like carriers to the crystal’s electronic properties, consistent with the theoretical band structure [refer to bands marked by blue arrows in Figure (d)] and prior observations from transport and the system’s thermoelectric properties. − Nevertheless, the predicted energy position of the saddle point is deeper in energy (at E ≈ −0.1 eV) than that observed in these measurements (at E ≈ −0.02 eV), likely attributable to slight doping of the Nb 3 SiTe 6 crystal during its synthesis.…”

“…Moreover, our careful k z band mappings indicate that the nodal line associated with these hourglass dispersions is periodic every two Brillouin zones (BZs), as verified by our DFT calculations of the spectral function. Also, a saddle-like Fermi surface has been mapped, which supports prior evidence from transport − for the dominance of hole carriers in the system’s electronic properties. Lastly, in situ K doping of Nb 3 SiTe 6 during ARPES facilitated the examination of other band crossings and parabolic bands at the zone center that are associated with nodal loop dispersions.…”

Revealing large room-temperature Nernst coefficients in 2D materials by first-principles modeling

“…There have been significant recent advancements aimed at enhancing the overall efficiency of TEGs and thermionic energy converters through the discovery of materials with exceptional properties. 10–14 As a great illustration, superior thermoelectric conversion efficiencies were reported in thin films, 15 2D alloys, 16 Janus monolayers, 17 high-mobility 2D electron gases, 18 layered materials, 19,20 superlattices, 21,22 graphene TEGs, 23 and nanostructured/heterostructured 2D materials. 24…”

“…There have been significant recent advancements aimed at enhancing the overall efficiency of TEGs and thermionic energy converters through the discovery of materials with exceptional properties. [10][11][12][13][14] As a great illustration, superior thermoelectric conversion efficiencies were reported in thin films, 15 2D alloys, 16 Janus monolayers, 17 highmobility 2D electron gases, 18 layered materials, 19,20 Peter Schindler Dr Peter Schindler is leading the Data-Driven Renewables Research (D2R2) group at Northeastern University (d2r2group.com) that seeks to discover novel materials for renewable energy applications using high-throughput, quantum chemistry calculations, and data-driven materials property predictions. He is a scientific advisory board member at Aionics Inc.…”