Abstract

Polar crystals can enable strong light-matter interaction at an infrared regime and provide many practical applications including thermal emission. However, the dynamic control of thermal emission based on polar crystals remains elusive as the lattice vibrations are solely determined by the crystal structure. Here, a nonvolatile tunable midinfrared thermal emitter enabled by a phase-changing film Ge2Sb2Te5 on silicon carbide polar crystal is demonstrated. By controlling the state of Ge2Sb2Te5 from an amorphous to a crystalline state, the emissivity of the thermal emitter is tuned from a low value to near unity with a maximum change in peak emissivity exceeding 10 dB over the Reststrahlen band of SiC (11.4 μm to 12.3 μm). This nonvolatile tunable thermal emitter, which presents a lot of advantages in terms of tunability, zero static power, angular insensitivity, and ease of fabrication, can be potentially applied for light sources, infrared camouflage, and radiative cooling devices.