Materials discovery extends beyond the synthesis of new compounds. Detailed characterization is essential to understand the potential applications of novel materials. However, experimental characterization can be challenging due to the vast chemical and physical spaces, as well as the specific conditions required for certain techniques. Computational high-throughput methods can overcome these challenges. In this work, the transport and thermoelectric properties of the recently synthesized bulk BiN are explored, including the effects of temperature, pressure, carrier concentration, polymorphism and polycrystalline grain size. We find that the band structure is strongly dependent on pressure and the polymorph studied. Both polymorphs exhibit low thermal conductivity at 0 GPa, which rapidly increases when pressure is applied. Electronic transport properties can be finely tuned based on the effects of pressure and polymorph type on the band gap, carrier mobilities, and presence of secondary pockets. The thermoelectric figure of merit can reach values around 0.85 for both p- and n-type BiN if the power factor and lattice thermal conductivity are optimized at 600 K, making this material competitive with other well-known thermoelectric families, such as Bi₂Te₃ or PbX, in the low-to-medium temperature range.

中文翻译：

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通过多晶型、压力和纳米结构增强 BiN 的热电品质因数


材料发现不仅限于新化合物的合成。详细的表征对于了解新型材料的潜在应用至关重要。然而，由于巨大的化学和物理空间以及某些技术所需的特定条件，实验表征可能具有挑战性。计算高通量方法可以克服这些挑战。在这项工作中，探讨了最近合成的体 BiN 的输运和热电性能，包括温度、压力、载流子浓度、多晶性和多晶晶粒尺寸的影响。我们发现能带结构强烈依赖于压力和所研究的多晶型物。两种多晶型物在 0 GPa 时都表现出低导热率，当施加压力时，热导率会迅速增加。电子传输特性可以根据压力和多晶型类型对带隙、载流子迁移率和次级口袋存在的影响进行微调。如果功率因数和晶格热导率在 600 K 下进行优化，则 p 型和 n 型 BiN 的热电品质因数可以达到 0.85 左右，这使得这种材料在中低温范围内与其他众所周知的热电系列（如 Bi₂Te₃ 或 PbX）具有竞争力。