Boosting Thermoelectric Performance of Cu3SbSe4-Based Diamond-Like Compounds via Multi-Scale Microstructure Engineering

en This link goes to a English section zh This link goes to a Chinese section Harnessing the potential of thermoelectric technology to convert waste heat into electricity, this study sought to enhance overall energy utilization efficiency and contribute to sustainable development through the advancement of environmentally friendly direct-conversion materials. Focusing on Cu 3 SbSe 4 -based diamond-like compounds, which are limited by low carrier concentration and high lattice thermal conductivity, we proposed and implemented a synergistic optimization strategy centered on multiscale microstructure engineering. Through employing ternary co-alloying with Ge, Te, and CuAlSe 2 , a multiscale heterogeneous microstructure comprising point defects, nano-precipitates, dislocations, and phase boundaries was successfully constructed, which not only enhanced the carrier concentration and optimized the band structure but also enabled full-spectrum phonon scattering, which dramatically suppressed the lattice thermal conductivity to near its amorphous limit while preserving a comparatively high power factor. Consequently, the optimized material attained a zT of ∼1.38 at 650 K and an average zT avg of ∼0.61, accompanied by significantly enhanced mechanical robustness and thermal stability, thereby demonstrating its promising applicability in mid-temperature thermoelectric power generation. This work ultimately established an effective paradigm for the synergistic regulation of electrical and thermal transport properties in Cu 3 SbSe 4 -based systems via multicomponent alloying. 摘要 en This link goes to a English section zh This link goes to a Chinese section 利用热电技术将废热转化为电能的潜力,这项研究试图通过推进环保的直接转换材料来提高整体能源利用效率,并为可持续发展做出贡献。针对低载流子浓度和高晶格热导率限制的Cu 3 SbSe 4 基类金刚石化合物,我们提出并实施了一种以多尺度微观结构工程为中心的协同优化策略。通过Ge、Te和CuAlSe 2 进行三元共合金化,成功构建了一个由点缺陷、纳米沉淀物、位错和相边界组成的多尺度非均匀结构。不仅提高了载体浓度,细化了电子能带结构,还诱导了全谱声子散射,在保持相对较高的功率因数的同时,大大抑制了晶格热导率, 接近其非晶极限。因此,优化后的材料在650 K下的 zT 约为1.38,平均 zT avg 约为0.61,同时显著提高了机械可靠性和热稳定性。从而证明了其在中温热电发电中的广阔应用前景。这项工作最终为通过多组分合金化协同调节Cu 3 SbSe 4 基体系的电和热输运性能建立了一个有效的范式。