Bi2Te3 single crystals with high room-temperature thermoelectric performance enhanced by manipulating point defects based on first-principles calculation
| Autor: | Peng-Peng Shang, Jun Pei, Zhihang Shan, Kaibin Wen, Zhiyue Zhang, Haiyun Gu, Tang Chunmei, Zhi-Cheng Huang, Bo-Ping Zhang |
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| Rok vydání: | 2019 |
| Předmět: |
Work (thermodynamics)
Materials science Condensed matter physics General Chemical Engineering Primitive cell 02 engineering and technology General Chemistry Power factor Electronic structure 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Crystallographic defect 0104 chemical sciences Temperature gradient Thermal conductivity Thermoelectric effect 0210 nano-technology |
| Zdroj: | RSC Advances. 9:14422-14431 |
| ISSN: | 2046-2069 |
| DOI: | 10.1039/c9ra01738k |
| Popis: | Intrinsic Bi2Te3 is a representative thermoelectric (TE) material with high performance at low temperature, which enables applications for electronic cooling. However, antisite defects easily form in p-type Bi2Te3, resulting in the difficulty of further property enhancement. In this work, the formation energy of native point defects in Bi2Te3 supercells and the electronic structure of Bi2Te3 primitive unit cell were calculated using first-principles. The antisite defect Bi_Te1 has a lower formation energy (0.68 eV) under the Te-lack condition for p-type Bi2Te3. The effects of point defects on TE properties were investigated via a series of p-type Bi2Te3−x (x = 0, 0.02, 0.04, 0.06, 0.08) single crystals prepared by the temperature gradient growth method (TGGM). Apart from the increased power factor (PF∥) which originates from the increased carrier concentration (n∥) and m*, the thermal conductivity (κ∥) was also cut down by the increased point defects. Benefitting from the high PF∥ of 4.09 mW m−1 K−2 and the low κ∥ of 1.77 W m−1 K−1, the highest ZT∥ of 0.70 was obtained for x = 0.06 composition at 300 K, which is 30% higher than that (0.54) of the intrinsic Bi2Te3. |
| Databáze: | OpenAIRE |
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