Effect of Silicon and Sodium on Thermoelectric Properties of Thallium-Doped Lead Telluride-Based Materials

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• 作者：Qinyong Zhang ; Hengzhi Wang ; Qian Zhang ; Weishu Liu ; Bo Yu ; Hui Wang ; Dezhi Wang ; George Ni ; Gang Chen ; Zhifeng Ren
• 刊名：Nano Letters
• 出版年：2012
• 出版时间：May 9, 2012
• 年：2012
• 卷：12
• 期：5
• 页码：2324-2330
• 全文大小：458K
• 年卷期：v.12,no.5(May 9, 2012)
• ISSN：1530-6992

文摘

Thallium (Tl)-doped lead telluride (Tl_0.02Pb_0.98Te) 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_0.02Pb_0.98Te 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_0.02Pb_0.98Te sample is the direct result of concurrent electron and phonon engineering by improving the power factor and lowering the thermal conductivity, respectively.

Keywords:

Thermoelectric materials; lead telluride; mechanical strength; silicon; sodium