There is a continuing need for the development of cost-effective and
sustainable mid-infrared light sources for applications such as gas sensing and infrared
beacons. A natural replacement for the conventional incandescent sources still widely used
in such applications are semiconductor LEDs, but to achieve emission at long ...
There is a continuing need for the development of cost-effective and
sustainable mid-infrared light sources for applications such as gas sensing and infrared
beacons. A natural replacement for the conventional incandescent sources still widely used
in such applications are semiconductor LEDs, but to achieve emission at long wavelengths
requires the realization of devices with narrow effective bandgaps, inherently leading to
relatively poor internal and external quantum efficiencies. Recently, the technological
potential of graphene-based incandescent emitters has been recognized, in part due to the
ability of graphene to sustain extremely large current densities. Here we introduce a simple
architecture, consisting of a back-reflector behind a multilayer graphene filament, which we
use to produce emitters with wall-plug-efficiencies comparable to state-of-the art
semiconductor cascade LEDs. Coupled with the potential for high-speed modulation,
resulting from the low thermal mass, our results demonstrate the feasibility of creating
practicable infrared sources.
