Physics

Infrared

Nanotechnology

Plasmon

Optics

Temperature gradient

Band gap

Photon

Responsivity

Materials science

Photodetector

Graphene

Chemical vapor deposition

Quantum mechanics

Optoelectronics

Thermoelectric effect

Photodetection

Thermodynamics

Nature Communications

Due to the low photon energy, detection of infrared photons is challenging at room temperature. Thermoelectric effect offers an alternative mechanism bypassing material bandgap restriction. In this article, we demonstrate an asymmetric plasmon-induced hot-carrier Seebeck photodetection scheme at room temperature that exhibits a remarkable responsivity of 2900 VW −1 , detectivity of 1.1 × 10 9 Jones along with a fast response of ~100 ns in the technologically relevant 8–12 µm band. This is achieved by engineering the asymmetric electronic environment of the generated hot carriers on chemical vapor deposition grown large area nanopatterned monolayer graphene, which leads to a temperature gradient of 4.7 K across the device terminals for an incident power of 155 nW, thereby enhancing the photo-thermoelectric voltage by manifold compared to previous reports. The results presented outline a strategy for uncooled, tunable, and multispectral infrared detection.

Dirac plasmon-assisted asymmetric hot carrier generation for room-temperature infrared detection