Ultrafast thermoelectric properties of gold under conditions of strong electron-phonon nonequilibrium
Ultrafast thermoelectric properties of gold under conditions of strong electron-phonon nonequilibrium
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DOI：
10.1063/1.3511341
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发表时间：
2010-11
影响因子：
3.2
通讯作者：
P. Hopkins;M. Bauer;J. Duda;J. Smoyer;T. English;P. Norris;T. Beechem;D. Stewart
中科院分区：
文献类型：
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作者：
P. Hopkins;M. Bauer;J. Duda;J. Smoyer;T. English;P. Norris;T. Beechem;D. Stewart
超短脉冲激光加热后金属中的电子散射速率可能与自由电子理论预测的有很大不同。在超短脉冲吸收和随后的热化之后实现的大电子温度可以导致远低于费米能量的电子轨道的亚导带热激发的激发。在贵金属的情况下，它们都具有远低于费米能的几个电子伏特的特征平坦d带，d带激发的开始已经被证明会增加电子-声子散射率一个数量级。在本文中，我们研究了这些大的电子热激发的超快热电输运性质的金，一个特征的贵金属的影响。在较强的电子-声子非平衡条件下（较高的电子温度和较低的晶格温度），我们发现Wiedemann-Franz定律被打破，塞贝克系数被降低。
The electronic scattering rates in metals after ultrashort pulsed laser heating can be drastically different than those predicted from free electron theory. The large electron temperature achieved after ultrashort pulsed absorption and subsequent thermalization can lead to excitation of subconduction band thermal excitations of electron orbitals far below the Fermi energy. In the case of noble metals, which all have a characteristic flat d-band several electron volts well below the Fermi energy, the onset of d-band excitations has been shown to increase electron-phonon scattering rates by an order of magnitude. In this paper, we investigate the effects of these large electronic thermal excitations on the ultrafast thermoelectric transport properties of gold, a characteristic noble metal. Under conditions of strong electron-phonon nonequilibrium (relatively high electron temperatures and relatively low lattice temperatures, Te⪢TL), we find that the Wiedemann–Franz law breaks down and the Seebeck coefficien...