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 SrTi_1-xNb _x O₃|11 unit cell SrTiO₃]₁₀-there are two different de Broglie wavelength in the SrTi_1-xNb _x O₃ system. The maximum power factor of the superlattice composed of the longer de Broglie wavelength SrTi_1-xNb _x O₃ exceeded ∼5 mW m^-1 K^-2, which doubles the value of optimized bulk SrTi_1-xNb _x O₃. The present approach-use of longer de Broglie wavelength-is epoch-making and is fruitful to design good thermoelectric materials showing high power factor.

中文翻译：

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二维电子系统的双热电功率因数。

二维电子系统作为热电材料已经引起了人们的关注，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，我们通过实验澄清了增强的二维可以有效地提高热电功率因数。我们制造的超晶格[N单元电池SrTi _1-x Nb的_X ö ₃ | 11单元电池的SrTiO ₃ ] ₁₀ -有在SrTi两个不同的德布罗意波长_1-xNb _x O ₃系统。由更长的布罗意利波长SrTi _1-x Nb _x O ₃组成的超晶格的最大功率因数超过了〜5 mW m ^-1  K ^-2，这使优化的体SrTi _1-x Nb _x O ₃的值翻了一番。本发明使用更长的德布罗意波长的方法是划时代的，并且对于设计显示出高功率因数的良好热电材料是有益的。