Optimal band gap for improved thermoelectric performance of two-dimensional Dirac materials
| Autor: | Bobby E. Gunara, Nguyen T. Hung, Eddwi H. Hasdeo, Muhammad Y. Hanna, Lukas P. A. Krisna, Ahmad R. T. Nugraha |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Physics Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Band gap Dirac (software) FOS: Physical sciences General Physics and Astronomy 02 engineering and technology 021001 nanoscience & nanotechnology Thermoelectric materials 01 natural sciences Boltzmann equation symbols.namesake Thermal conductivity Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences Boltzmann constant Thermoelectric effect symbols Figure of merit 0210 nano-technology |
| Popis: | Thermoelectric properties of two-dimensional (2D) Dirac materials are calculated within linearized Boltzmann transport theory and relaxation time approximation. We find that the gapless 2D Dirac material exhibits poorer thermoelectric performance than the gapped one. Furthermore, there exists an optimal band gap for maximizing the figure of merit (ZT) in the gapped 2D Dirac material. The optimal band gap ranges from 6kBT to 18kBT, where kB is the Boltzmann constant and T is the operating temperature in kelvin. This result, which is similar to that for bulk semiconductors, indicates the importance of having narrow gaps to achieve the best thermoelectrics in 2D systems. Larger maximum ZTs can also be obtained by suppressing the lattice thermal conductivity. In the most ideal case where the lattice thermal conductivity is zero (leaving the electron thermal conductivity alone), the maximum ZT in the gapped 2D Dirac material is many times ZT of commercial thermoelectric materials. 10 pages, 11 figures, accepted to Jour. Appl. Physics |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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