School of Material Science and Engineering, Xihua University, Chengdu, Sichuan 610039, PR China.
Nano Lett. 2012 May 9;12(5):2324-30. doi: 10.1021/nl3002183. Epub 2012 Apr 20.
Thallium (Tl)-doped lead telluride (Tl(0.02)Pb(0.98)Te) thermoelectric materials fabricated by ball milling and hot pressing have decent thermoelectric properties but weak mechanical strength. Addition of silicon (Si) nanoparticles strengthened the mechanical property by reducing the grain size and defect density but resulted in low electrical conductivity that was not desired for any thermoelectric materials. Fortunately, doping of sodium (Na) into the Si added Tl(0.02)Pb(0.98)Te brings back the high electrical conductivity and yields higher figure-of-merit ZT values of ∼1.7 at 770 K. The ZT improvement by Si addition and Na doping in Tl(0.02)Pb(0.98)Te sample is the direct result of concurrent electron and phonon engineering by improving the power factor and lowering the thermal conductivity, respectively.
掺铊（Tl）的碲化铅（Tl(0.02)Pb(0.98)Te）热电材料通过球磨和热压制备，具有相当好的热电性能，但机械强度较弱。添加硅（Si）纳米颗粒通过减小晶粒尺寸和缺陷密度来增强机械性能，但导致电导率降低，这不是任何热电材料所期望的。幸运的是，将钠（Na）掺杂到添加 Si 的 Tl(0.02)Pb(0.98)Te 中，可恢复高电导率，并在 770 K 时获得更高的品质因数 ZT 值约为 1.7。Si 添加和 Na 掺杂在 Tl(0.02)Pb(0.98)Te 样品中的 ZT 提高是通过分别提高功率因子和降低热导率来协同进行电子和声子工程的直接结果。
