• 文献标题:   Ultra-broadband photodetectors based on epitaxial graphene quantum dots
  • 文献类型:   Article
  • 作  者:   EL FATIMY A, NATH A, KONG BD, BOYD AK, MYERSWARD RL, DANIELS KM, JADIDI MM, MURPHY TE, GASKILL DK, BARBARA P
  • 作者关键词:   graphene, hotelectron bolometer, quantum dot
  • 出版物名称:   NANOPHOTONICS
  • ISSN:   2192-8606 EI 2192-8614
  • 通讯作者地址:   Georgetown Univ
  • 被引频次:   5
  • DOI:   10.1515/nanoph-2017-0100
  • 出版年:   2018

▎ 摘  要

Graphene is an ideal material for hot-electron bolometers due to its low heat capacity and weak electron-phonon coupling. Nanostructuring graphene with quantum-dot constrictions yields detectors of electromagnetic radiation with extraordinarily high intrinsic responsivity, higher than 1 x 10(9) V W -1 at 3 K. The sensing mechanism is bolometric in nature: the quantum confinement gap causes a strong dependence of the electrical resistance on the electron temperature. Here, we show that this quantum confinement gap does not impose a limitation on the photon energy for light detection and these quantum-dot bolometers work in a very broad spectral range, from terahertz through telecom to ultraviolet radiation, with responsivity independent of wavelength. We also measure the power dependence of the response. Although the responsivity decreases with increasing power, it stays higher than 1 x 10(8) V W-1 in a wide range of absorbed power, from 1 pW to 0.4 nW.