Photo-thermoelectric detection of cyclotron resonance in asymmetrically carrier-doped graphene two-terminal device
Photo-thermoelectric detection of cyclotron resonance in asymmetrically carrier-doped graphene two-terminal device
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DOI：
10.1063/1.5045731
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发表时间：
2018-09
影响因子：
4
通讯作者：
Kei Kinoshita;R. Moriya;M. Arai;S. Masubuchi;Kenji Watanabe;T. Taniguchi;T. Machida
中科院分区：
文献类型：
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作者：
Kei Kinoshita;R. Moriya;M. Arai;S. Masubuchi;Kenji Watanabe;T. Taniguchi;T. Machida
已知石墨烯显示出可以超过其光伏贡献的显著光电效应。在这里，通过利用这种效应，我们证明了在双背栅h-BN/石墨烯/h-BN双端器件的回旋共振的光电压测量。除了p型掺杂的Si全局背栅之外，还制造了石墨局部底栅。通过调节两个栅极电压，产生具有不对称载流子掺杂分布的面内石墨烯结。借助于这种非对称结构，检测到在金属电极/石墨烯结附近产生的光热电电压。在低温和存在磁场的情况下，在红外激光（波长= 9.28至10.61微米）的照射下测量光感应电压。在回旋共振条件下，我们观察到光电压信号的强烈增强，在该条件下，激发能量与朗道能级之间的跃迁相一致。这些结果突出了利用石墨烯中的光电热效应进行太赫兹光探测的可能性。
Graphene is known to show a significant photo-thermoelectric effect that can exceed its photovoltaic contribution. Here, by utilizing this effect, we demonstrate a photovoltage measurement of cyclotron resonance in a double-back-gated h-BN/graphene/h-BN two-terminal device. A graphite local bottom gate was fabricated in addition to a p-doped Si global back gate. By tuning the two gate voltages, an in-plane graphene junction having an asymmetric carrier-doping profile was created. With the help of this asymmetric structure, the photo-thermoelectric voltage generated in the vicinity of the metal-electrode/graphene junction was detected. At a low temperature and in the presence of a magnetic field, a photo-induced voltage was measured under the irradiation of an infrared laser (Wavelength= 9.28 to 10.61 micron). We observed a strong enhancement of the photovoltage signal under the cyclotron resonance condition, at which the energy of excitation coincides with a transition between Landau levels. These results highlight the possibility of using the photo-thermoelectric effect in graphene for THz photo-detection.