This paper demonstrates nanoscale infrared thermal imaging in electrically biased bilayer graphene (BLG) by using a scattering-type scanning near-field optical microscope (s-SNOM). s-SNOM provides a noncontact technique to detect the thermally excited electromagnetic evanescent fields (~21 THz) generated on the surface of a Joule-heated BLG. With increasing bias current, a strong near-field signal appears mainly in the sub-micrometer-sized constricted region. The temperature mapping of the graphene film can be derived from the infrared near-field signals, and shows good agreement with the finite-element simulation. Hence, we prove that s-SNOM is a potential infrared nano-thermography for the graphene device.

中文翻译：

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通过近场光学显微镜对电偏置石墨烯中的热激发渐逝场进行纳米级探测

本文通过使用散射型扫描近场光学显微镜 (s-SNOM) 在电偏置双层石墨烯 (BLG) 中演示纳米级红外热成像。s-SNOM 提供了一种非接触式技术来检测在焦耳加热的 BLG 表面上产生的热激发电磁倏逝场 (~21 THz)。随着偏置电流的增加，强近场信号主要出现在亚微米大小的收缩区域。石墨烯薄膜的温度映射可以从红外近场信号导出，并且与有限元模拟显示出良好的一致性。因此，我们证明 s-SNOM 是石墨烯器件的潜在红外纳米热成像。