Figure 1.

(a) Schematic structure of device consisting of laminated layers of MLG film, an electrolyte layer in the polyethylene membrane, and a back electrode. The thermal characterization setup includes an LWIR or MWIR camera, a hot plate, and a voltage source. (b) Schematic drawing of the mechanism of ionic liquid intercalation of a multilayer graphene film initiated by the defects at the grain boundaries followed by diffusion of ions between the layers. (c) Photograph of the infrared device fabricated on a printed circuit board using gold-plated electrodes laminated by electrolyte and graphene layers. (d, e) Thermal camera images of the device at high and low emissivity states recorded by (d) MWIR (3–5 μm) and (e) LWIR (8–14 μm) cameras. Broad tunable absorption of graphene enables modulation of apparent temperature both at mid- and long-infrared wavelength.