Department of physics, Lancaster University, Lancaster LA1 4YB, UK.
Nanoscale. 2016 Jul 14;8(28):13597-602. doi: 10.1039/c6nr02291j.
If fullerene-based thermoelectricity is to become a viable technology, then fullerenes exhibiting both positive and negative Seebeck coefficients are needed. C60 is known to have a negative Seebeck coefficient and therefore in this paper we address the challenge of identifying a positive-Seebeck-coefficient fullerene. We investigated the thermoelectric properties of single-molecule junctions of the exohedral fullerene C50Cl10 connected to gold electrodes and found that it indeed possesses a positive Seebeck coefficient. Furthermore, in common with C60, the Seebeck coefficient can be increased by placing more than one C50Cl10 in series. For a single C50Cl10, we find S = +8 μV K(-1) and for two C50Cl10's in series we find S = +30 μV K(-1). We also find that the C50Cl10 monomer and dimer have power factors of 0.5 × 10(-5) W m(-1) K(-2) and 6.0 × 10(-5) W m(-1) K(-2) respectively. These results demonstrate that exohedral fullerenes provide a new class of thermoelectric materials with desirable properties, which complement those of all-carbon fullerenes, thereby enabling the boosting of the thermovoltage in all-fullerene tandem structures.
如果富勒烯基热电学要成为一种可行的技术，那么需要同时具有正、负塞贝克系数的富勒烯。已知 C60 具有负塞贝克系数，因此在本文中，我们致力于寻找具有正塞贝克系数的富勒烯。我们研究了连接到金电极的外笼型富勒烯 C50Cl10 单分子结的热电性质，发现它确实具有正塞贝克系数。此外，与 C60 一样，通过将多个 C50Cl10 串联连接，可以增加塞贝克系数。对于单个 C50Cl10，我们发现 S = +8 μV K(-1)，而对于两个 C50Cl10 的串联，我们发现 S = +30 μV K(-1)。我们还发现 C50Cl10 单体和二聚体的功率因子分别为 0.5 × 10(-5) W m(-1) K(-2)和 6.0 × 10(-5) W m(-1) K(-2)。这些结果表明，外笼型富勒烯提供了一类具有理想性质的新型热电材料，与全碳富勒烯互补，从而能够提高全富勒烯串联结构中的热电压。
