首页> 外文OA文献 >Transport properties and valence band feature of high-performance (GeTe)_(85)(AgSbTe_2)_(15) thermoelectric materials
【2h】

Transport properties and valence band feature of high-performance (GeTe)_(85)(AgSbTe_2)_(15) thermoelectric materials

机译:高性能(GeTe)_(85)(AgSbTe_2)_(15)热电材料的输运性质和价带特征

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

This paper aims at elucidating the origin of the high thermoelectric power factor of p-type (AgxSbTe_(x/2+1.5)15)(GeTe)_(85) (TAGS) thermoelectric materials with 0.4 ≤ x ≤ 1.2. All samples exhibit good thermoelectric figures of merit (zT) which reach 1.5 at 700 K for x = 0.6. Thermoelectric and thermomagnetic transport properties (electrical resistivity, Seebeck, Hall and transverse Nernst–Ettinghausen coefficients) are measured and used to calculate the scattering factor, the Fermi energy, the density-of-states (DOS) effective mass and hole mean free path (mfp). The DOS effective mass is very high due to the large band mass of the primary valence band and the high degeneracy of pockets in the Fermi surface from the second valence band. The highly degenerate Fermi surface increased the total DOS without decreasing mobility, which is more desirable than the high DOS that comes from a single carrier pocket. The high-temperature hole mfp approaches the Ioffe–Regel limit for band-type conduction, which validates our discussion based on band transport and is also important for TAGS alloys having high zT with heavy bands. The present results show that multiple degenerate Fermi surface pockets provide an effective way of substantially increasing the power factor of thermoelectric materials with low thermal conductivity.
机译:本文旨在阐明0.4≤x≤1.2的p型(AgxSbTe_(x / 2 + 1.5)15)(GeTe)_(85)(TAGS)热电材料的高热电功率因数的起源。所有样品均表现出良好的热电品质因数(zT),在700 K时x = 0.6时达到1.5。测量热电和热磁传输特性(电阻率,塞贝克,霍尔和横向能斯特-埃廷豪森系数),并用于计算散射因子,费米能量,状态密度(DOS)有效质量和空穴平均自由程( mfp)。 DOS有效质量很高,这是因为初级价带的带质量大,并且费米表面中的囊从第二价带起的高度简并性。高度退化的费米表面在不降低迁移率的情况下增加了总DOS,这比来自单个载流子袋的高DOS更可取。高温空穴的mfp接近能带型导通的Ioffe-Regel极限,这验证了我们基于能带传输的讨论,对于具有高zT和重能带的TAGS合金也很重要。目前的结果表明,多个简并的费米表面凹坑提供了一种有效地提高具有低导热率的热电材料的功率因数的有效方法。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号