Yusupov Khabib, Inerbaev Talgat, Råsander Mikael, Pankratova Daria, Concina Isabella, Larsson Andreas J, Vomiero Alberto
Institute of Physics, Chemistry and Biology (IFM), Linkoping University, 583 30, Linkoping, Sweden.
Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk 630090, Russia.
iScience. 2021 Sep 16;24(10):103145. doi: 10.1016/j.isci.2021.103145. eCollection 2021 Oct 22.
Thermoelectric materials convert waste heat into electric energy. Oxyselenide-based material, specifically, p-type BiCuSeO, is one of the most promising materials for these applications. There are numerous approaches to improve the heat-to-electricity conversion performance. Usually, these approaches are applied individually, starting from the pure intrinsic material. Higher performance could, however, be reached by combining a few strategies simultaneously. In the current work, yttrium, niobium, and phosphorous substitutions on the bismuth sites in already bismuth-deficient BiCuSeO systems were investigated via density functional theory. The bismuth-deficient system was used as the reference system for further introduction of substitutional defects. The substitution with phosphorous showed a decrease of up to 40 meV (11%) in the energy gap between conduction and valence bands at the highest substitution concentration. Doping with niobium led to the system changing from a p-type to an n-type conductor, which provides a possible route to obtain n-type BiCuSeO systems.
热电材料可将废热转化为电能。具体而言，基于氧硒化物的材料，即p型BiCuSeO，是这些应用中最具潜力的材料之一。有许多方法可提高热电转换性能。通常，这些方法是从纯本征材料开始单独应用的。然而，通过同时结合几种策略，可以实现更高的性能。在当前工作中，通过密度泛函理论研究了在已经缺铋的BiCuSeO体系中铋位点上的钇、铌和磷取代情况。缺铋体系被用作进一步引入替代缺陷的参考体系。在最高取代浓度下，用磷取代导致导带和价带之间的能隙降低了40毫电子伏特（11%）。用铌掺杂导致体系从p型导体转变为n型导体，这为获得n型BiCuSeO体系提供了一条可能的途径。
