Plasmon induced thermoelectric effect in graphene
Plasmon induced thermoelectric effect in graphene
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DOI：
10.1038/s41467-018-07508-z
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发表时间：
2018-12-05
影响因子：
16.6
通讯作者：
Oulton, Rupert F.
中科院分区：
文献类型：
--
作者：
Shautsova, Viktoryia;Sidiropoulos, Themistoklis;Oulton, Rupert F.
由于石墨烯具有超快和宽带光探测的潜力，它已成为光电子学的一种有前途的材料。石墨烯结的光响应以两种相互竞争的光电流产生机制为特征：传统的光伏效应和更主要的热载子辅助光热电（PTE）效应。人们认为PTE效应依赖于石墨烯掺杂谱中塞贝克系数的变化。在存在电子温度梯度的情况下，第二种PTE效应可以发生在均匀的石墨烯通道上。在这里，我们研究了后一种效应，在纳米结构电接触存在的情况下，石墨烯载流子的强局部等离子体加热导致电子温度达到2000 K左右。在一定条件下，等离子体诱导的PTE光电流贡献可以被分离出来。在这种情况下，该装置有效地作为灵敏的电子温度计运行，因此代表了开发基于热载流子的等离子体器件的使能技术。
Graphene has emerged as a promising material for optoelectronics due to its potential for ultrafast and broad-band photodetection. The photoresponse of graphene junctions is characterized by two competing photocurrent generation mechanisms: a conventional photovoltaic effect and a more dominant hot-carrier-assisted photothermoelectric (PTE) effect. The PTE effect is understood to rely on variations in the Seebeck coefficient through the graphene doping profile. A second PTE effect can occur across a homogeneous graphene channel in the presence of an electronic temperature gradient. Here, we study the latter effect facilitated by strongly localised plasmonic heating of graphene carriers in the presence of nanostructured electrical contacts resulting in electronic temperatures of the order of 2000 K. At certain conditions, the plasmon-induced PTE photocurrent contribution can be isolated. In this regime, the device effectively operates as a sensitive electronic thermometer and as such represents an enabling technology for development of hot carrier based plasmonic devices.