2021/07/29 by Muthusamy Omprakash, Omprakash, Muthusamy, Saurabh Singh +18
Materials Science · Physics and Astronomy · #Advanced Thermoelectric Materials and Devices #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Semiconductor materials and interfaces #Thermal properties of materials #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.2107.13778
47 pages, 15 figures
arxiv created 2021/07/29 · openalex publication_date 2021/07/29 · arxiv updated 2021/07/30 · openalex created_date 2021/08/02 · openalex updated_date 2026/07/28
For simultaneously achieving the high-power factor and low lattice thermal conductivity of Si-Ge based thermoelectric materials, we employed, in this study, constructively modifying the electronic structure near the chemical potential and nano-structuring by low temperature and high-pressure sintering on nano-crystalline powders. Nickel was doped to create the impurity states near the edge of the valence band for enhancing the power factor with boron for tuning the carrier concentration. The nanostructured samples with the nominal composition of Si0.65-xGe0.32Ni0.03Bx (x = 0.01, 0.02, 0.03, and 0.04) were synthesized by the mechanical alloying followed low-temperature and high-pressure sintering process. A large magnitude of Seebeck coefficient reaching 321 μVK-1 together with a small electrical resistivity of 4.49 mΩcm, leads to a large power factor of 2.3 Wm-1K-2 at 1000 K. With successfully reduced thermal conductivity down to 1.47 Wm-1K-1, a large value of ZT ~1.56 was obtained for Si0.65-xGe0.32Ni0.03B0.03 at 1000 K