采用真空熔炼、机械球磨及放电等离子烧结技术 (SPS) 制备得到了(Ag2Te)x(Bi0.5Sb1.5Te3)1-x (x= 0, 0.025, 0.05, 0.1) 系列样品, 性能测试表明, Ag2Te的掺入可以显著改变材料的热电性能变化趋势, 掺杂样品在温度为450~550 K范围内具有较未掺杂样品更优的热电性能. 适当量的Ag2Te掺入能够有效地提高材料的声子散射, 降低材料的热导率. 在测试温度范围内, (Ag2Te)0.05(Bi0.5Sb1.5Te3)0.95具有最低的晶格热导, 室温至575 K范围内保持在0.2 ~ 0.3 W/(m·K)之间, 在575 K时, (Ag2Te)0.05(Bi0.5Sb1.5Te3)0.95试样具有最大热电优值ZT = 0.84, 相较于未掺杂样品提高了约20%.
(Ag2Te)x(Bi0.5Sb1.5Te3)1-x(x=0, 0.025, 0.05, 0.1) alloys were synthesized by “Melting-Ball Milling-Spark Plasma Sintering” method. Transport properties measurements indicate that the Ag2Te-doping can affect the temperature dependence of thermoelectric properties of the samples significantly. Samples with Ag2Te-doping have better thermoelectric performances in the temperature range from 450 K to 550 K. Appropriate amount of Ag2Te can enhance the phonon scattering of the alloys effectively, which lead to the lower thermal conductivities for these samples. Over the entire temperature range, sample (Ag2Te)0.05(Bi0.5Sb1.5Te3)0.95 exhibits the lowest lattice thermal conductivities, ranging within 0.2-0.3 W/(m·K) from room temperature to 575 K. The maximum ZT value of 0.84 is obtained at 575 K for the sample (Ag2Te)0.05(Bi0.5Sb1.5Te3)0.95. Compared with the one without doping, the ZT value is increased by almost 20%.
参考文献
| [1] | Dresselhaus M S, Chen G, Tang M Y, et al. New directions for low-dimensional thermoelectric materials. Advanced Materials, 2007, 19(8): 1043-1053.[2]Rowe D M. Thermoelectric Hanbook-Macro to Nano. Boca Raton: CRC Press, 2006.[3]Tritt T M. Thermoelectric materials - holey and unholey semiconductors. Science, 1999, 283(5403): 804-805.[4]Chung D Y, Hogan T, Brazis P, et al. CsBi4Te6: a high-performance thermoelectric material for low-temperature applications. Science, 2000, 287(5455): 1024-1027.[5]Ettenberg M H, Maddux J R, Taylor P J, et al. Improving yield and performance in pseudo-ternary thermoelectric alloys (Bi2Te3)(Sb2Te3) (Sb2Se3). Journal of Crystal Growth, 1997, 179(3/4): 495-502.[6]Yamashita O, Tomiyoshi S, Makita K. Bismuth telluride compounds with high thermoelectric figures of merit. Journal of Applied Physics, 2003, 93(1): 368-374.[7]Drabble J R, Goodman C H L. Chemical bonding in bismuth telluride. Journal of Physics and Chemistry of Solids, 1958, 5(1/2): 142-144.[8]Zhao X B, Ji X H, Zhang Y H, et al. Bismuth telluride nanotubes and the effects on the thermoelectric properties of nanotube-containing nanocomposites. Applied Physics Letters, 2005, 86(6): 062111-1-3.[9]Cao Y Q, Zhao X B, Zhu T J, et al. Syntheses and thermoelectric properties of Bi2Te3/Sb2Te3 bulk nanocomposites with laminated nanostructure. Applied Physics Letters, 2008, 92 (14): 143106-1-3.[10]Poudel B, Hao Q, Ma Y, et al. High-thermoelectric performance of nanostructured bismuth antimony telluride bulk alloys. Science, 2008, 320(5876): 634-638.[11]Ma Y, Hao Q, Poudel B, et al. Enhanced thermoelectric figure-of-merit in p-type nanostructured bismuth antimony tellurium alloys made from elemental chunks. Nano Letters, 2008, 8(8): 2580-2584.[12]Tang X F, Xie W J, Li H, et al. Preparation and thermoelectric transport properties of high-performance p-type Bi2Te3 with layered nanostructure. Applied Physics Letters, 2007, 90(1): 012102-1-3.[13]Xie W J, Tang X F, Yan Y G, et al. Unique nanostructures and enhanced thermoelectric performance of melt-spun BiSbTe alloys. Applied Physics Letters, 2009, 94(10): 102111-1-3.[14]Cui J L, Xiu W J, Xue H F. High thermoelectric properties of p-type pseudobinary (Cu4Te3)(x)-(Bi0.5Sb1.5Te3)(1-x) alloys prepared by spark plasma sintering. Journal of Applied Physics, 2007, 101(12): 123713-1-4.[15]Zhu P W, Imai Y, Yukihiro I, et al. High thermoelectric properties of PbTe doped with Bi2Te3 and Sb2Te3. Chinese Physics Letters, 2005, 22(8): 2103-2105.[16]Zhou X S, Deng Y, Nan C W, et al. Transport properties of SnTe-Bi2Te3 alloys. Journal of Alloys and Compounds, 2003, 352(1/2): 328-332.[17]Shen J J, Liu X X, Zhu T J, et al. Improved thermoelectric properties of La-doped Bi2Sr2Co2O9-layered misfit oxides. Journal of Materials Science, 2009, 44(7): 1889-1893.[18]Mi J L, Zhao X B, Zhu T J, et al. Improved thermoelectric figure of merit in n-type CoSb3 based nanocomposites. Applied Physics Letters, 2007, 91(2): 172116-1-3.[19]Rowe D M, Shukla V S, Savvides N. Phonon-scattering at grain-boundaries in heavily doped fine-grained silicon-germanium alloys. Nature, 1981, 290(5809): 765-766. |
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