Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology , Sichuan University , Chengdu 610064 , China.
Chongqing Institute of Green and Intelligent Technology , Chinese Academy of Sciences , Chongqing 400714 , China.
ACS Appl Mater Interfaces. 2018 Jul 5;10(26):22401-22407. doi: 10.1021/acsami.8b05117. Epub 2018 Jun 22.
P-type lead telluride (PbTe) emerged as a promising thermoelectric material for intermediate-temperature waste-heat-energy harvesting. However, n-type PbTe still confronted with a considerable challenge owing to its relatively low figure of merit ZT and conversion efficiency η, limiting widespread thermoelectric applications. Here, we report that Ga-doping in n-type PbTe can optimize carrier concentration and thus improve the power factor. Moreover, further experimental and theoretical evidence reveals that Ga-doping-induced multiphase structures with nano- to micrometer size can simultaneously modulate phonon transport, leading to dramatic reduction of lattice thermal conductivity. As a consequence, a tremendous enhancement of ZT value at 823 K reaches ∼1.3 for n-type PbGaTe. In particular, in a wide temperature range from 323 to 823 K, the average ZT value of ∼0.9 and the calculated conversion efficiency η of ∼13% are achieved by Ga doping. The present findings demonstrate the great potential in Ga-doped PbTe thermoelectric materials through a synergetic carrier tuning and multiphase engineering strategy.
P 型碲化铅（PbTe）作为一种很有前途的中温废热能源收集用热电材料而出现。然而，n 型 PbTe 仍然面临着相当大的挑战，因为其品质因数 ZT 和转换效率 η 相对较低，限制了广泛的热电应用。在这里，我们报告 Ga 掺杂 n 型 PbTe 可以优化载流子浓度，从而提高功率因数。此外，进一步的实验和理论证据表明，Ga 掺杂诱导的具有纳米到微米尺寸的多相结构可以同时调节声子输运，导致晶格热导率的显著降低。结果，n 型 PbGaTe 在 823 K 时的 ZT 值达到约 1.3，这是一个巨大的提高。特别是在 323 至 823 K 的宽温度范围内，通过 Ga 掺杂实现了约 0.9 的平均 ZT 值和约 13%的计算转换效率 η。本研究结果通过协同载流子调控和多相工程策略，证明了 Ga 掺杂 PbTe 热电材料具有巨大的潜力。
