title: Epitaxial graphene quantum dots for high-performance terahertz bolometers.
abstract: Light absorption in graphene causes a large change in electron temperature due to the low electronic heat capacity and weak electron-phonon coupling. This property makes graphene a very attractive material for hot-electron bolometers in the terahertz frequency range. Unfortunately, the weak variation of electrical resistance with temperature results in limited responsivity for absorbed power. Here, we show that, due to quantum confinement, quantum dots of epitaxial graphene on SiC exhibit an extraordinarily high variation of resistance with temperature (higher than 430 MΩ K(-1) below 6 K), leading to responsivities of 1 × 10(10) V W(-1), a figure that is five orders of magnitude higher than other types of graphene hot-electron bolometer. The high responsivity, combined with an extremely low electrical noise-equivalent power (∼2 × 10(-16) W Hz(-1/2) at 2.5 K), already places our bolometers well above commercial cooled bolometers. Additionally, we show that these quantum dot bolometers demonstrate good performance at temperature as high as 77 K.
authors.affiliation: Department of Physics, Georgetown University, Washington, Washington DC 20057, USA.
authors.forename: Abdel
authors.identifier: http://orcid.org/0000-0001-6500-7762
authors.initials: A
authors.lastname: El Fatimy
authors.affiliation: US Naval Research Laboratory, Washington, Washington DC 20375, USA.
authors.forename: Rachael L
authors.initials: RL
authors.lastname: Myers-Ward
authors.affiliation: US Naval Research Laboratory, Washington, Washington DC 20375, USA.
authors.forename: Anthony K
authors.initials: AK
authors.lastname: Boyd
authors.affiliation: US Naval Research Laboratory, Washington, Washington DC 20375, USA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Daniels
authors.affiliation: US Naval Research Laboratory, Washington, Washington DC 20375, USA.
authors.forename: D Kurt
authors.initials: DK
authors.lastname: Gaskill
authors.affiliation: Department of Physics, Georgetown University, Washington, Washington DC 20057, USA.
authors.forename: Paola
authors.initials: P
authors.lastname: Barbara