Two-dimensional electron systems have attracted attention as thermoelectric materials, which can directly convert waste heat into electricity. It has been theoretically predicted that thermoelectric power factor can be largely enhanced when the two-dimensional electron layer is far narrower than the de Broglie wavelength. Although many studies have been made, the effectiveness has not been experimentally clarified thus far. Here we experimentally clarify that an enhanced two-dimensionality is efficient to enhance thermoelectric power factor. We fabricated superlattices of [N unit cell SrTi1−xNbxO3|11 unit cell SrTiO3]10—there are two different de Broglie wavelength in the SrTi1−xNbxO3 system. The maximum power factor of the superlattice composed of the longer de Broglie wavelength SrTi1−xNbxO3 exceeded ∼5 mW m−1 K−2, which doubles the value of optimized bulk SrTi1−xNbxO3. The present approach—use of longer de Broglie wavelength—is epoch-making and is fruitful to design good thermoelectric materials showing high power factor.
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机译:二维电子系统作为热电材料已引起人们的关注,它可以将废热直接转化为电能。从理论上已经预测到,当二维电子层远小于德布罗意波长时,可以大大提高热电功率因数。尽管已经进行了许多研究,但是到目前为止,还没有通过实验澄清其有效性。在这里,我们通过实验弄清楚增强的二维可以有效地提高热电功率因数。我们制造了[N个晶胞SrTi1-xNbxO3 | 11晶胞SrTiO3] 10的超晶格-SrTi1-xNbxO3系统中有两个不同的de Broglie波长。由更长的Broglie波长SrTi1-xNbxO3组成的超晶格的最大功率因数超过了〜5 mW m -1 sup> K -2 sup>,这使优化的体SrTi1的值翻了一番-xNbxO3。目前的方法(使用更长的德布罗意波长)是划时代的,对于设计显示出高功率因数的良好热电材料很有用。
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