Tuning bands of PbSe for better thermoelectric efficiency
Tuning bands of PbSe for better thermoelectric efficiency
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DOI：
10.1039/c3ee43438a
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发表时间：
2014-02-01
影响因子：
32.5
通讯作者：
Snyder, G. Jeffrey
中科院分区：
文献类型：
--
作者：
Wang, Heng;Gibbs, Zachary M.;Snyder, G. Jeffrey
改善PbSe的热电性能超过其先前报道的最大zT可以通过设计其电子能带结构来实现。我们在这里证明，使用光学吸收光谱，第一原理计算，和依赖于温度的传输测量，合金PbSe与SrSe导致的带结构的显着变化，增加热电品质因数，ZT。两个价带会聚的温度随着Sr的添加而降低。的zT值，当载流子密度被优化，增加Sr添加在Pb 1-xSrSe和当x = 0.08时，在900 K的最大zT为1.5。zT的净效益来自能带结构调整，即使在其他热电固溶体中，是无序导致的热导率降低导致净zT改善。
Improving the thermoelectric performance of PbSe over its previously reported maximum zT can be achieved by engineering its electronic band structure. We demonstrate here, using optical absorption spectra, first principles calculations, and temperature dependent transport measurements, that alloying PbSe with SrSe leads to a dramatic change of the band structure that increases the thermoelectric figure of merit, zT. The temperature where the two valence bands converge decreases with Sr addition. The zT value, when the carrier density is optimized, increases with Sr addition in Pb1-xSrSe and when x = 0.08 a maximum zT of 1.5 at 900 K is achieved. The net benefit in zT comes from the band structure tuning even though in other thermoelectric solid solutions it is the thermal conductivity reduction from disorder that leads to net zT improvement.