Moço Duarte, Malta José F, Santos Luís F, Lopes Elsa B, Gonçalves António P
C2TN, DECN, Instituto Superior Técnico, Universidade de Lisboa, Campus Tecnológico e Nuclear, 2695-066 Bobadela, Portugal.
Centre for Physics of the University of Coimbra (CFisUC), Department of Physics, University of Coimbra, 3004-516 Coimbra, Portugal.
Materials (Basel). 2023 Jan 17;16(3):898. doi: 10.3390/ma16030898.
As the search continues for novel, cheaper, more sustainable, and environmentally friendly thermoelectric materials in order to expand the range of applications of thermoelectric devices, the tetrahedrite mineral (CuSbS) stands out as a potential candidate due to its high abundance, low toxicity, and good thermoelectric performance. Unfortunately, as most current thermoelectric materials achieve zTs above 1.0, ternary tetrahedrite is not a suitable alternative. Still, improvement of its thermoelectric performance has been achieved to zTs ≈ 1 via isovalent doping and composition tuning, but most studies were limited to a single doping element. This project explores the effects of simultaneous doping with nickel and selenium in the thermoelectric properties of tetrahedrite. Simulated properties for different stoichiometric contents of these dopants, as well as the measured thermoelectric properties of the correspondent materials, are reported. One of the samples, CuNiSbSSe, stands out with a high power factor = 1279.99 µW/m·K at 300 K. After estimating the thermal conductivity, a zT = 0.325 at 300 K was obtained for this composition, which is the highest for tetrahedrites for this temperature. However, analysis of the weighted mobility shows the presence of detrimental factors, such as grain boundaries, disorder, or ionized impurity scattering, pointing to the possibility of further improvements.
为了扩大热电器件的应用范围，人们不断寻找新型、更便宜、更可持续且环保的热电材料，硫锑铜矿矿物（CuSbS）因其储量丰富、毒性低且热电性能良好而成为潜在候选材料。不幸的是，由于目前大多数热电材料的zT值都高于1.0，三元硫锑铜矿并非合适的替代品。尽管如此，通过等价掺杂和成分调整，其热电性能已提高到zT≈1，但大多数研究仅限于单一掺杂元素。本项目探究了同时掺杂镍和硒对硫锑铜矿热电性能的影响。报告了这些掺杂剂不同化学计量含量的模拟性能以及相应材料的实测热电性能。其中一个样品CuNiSbSSe表现突出，在300 K时功率因子高达1279.99 μW/m·K。估算热导率后，该成分在300 K时的zT值为0.325，是该温度下硫锑铜矿的最高值。然而，对加权迁移率的分析表明存在有害因素，如晶界、无序或电离杂质散射，这表明仍有进一步改进的可能。
