Tunable nonreciprocal thermal emitter based on graphene/indium arsenide/silver microstructure

Abstract

Nonreciprocal thermal radiation has been studied by people. However, previous research has mainly focused on TM waves. Therefore, this article investigates a nonreciprocal transmitter based on TE transverse waves. Nonreciprocal emitters completely violate Kirchhoff's law and can be applied to various thermal radiation devices. However, there is little research on tunable nonreciprocal thermal emitters. In this article, we innovatively replace the previous top metal grating structure with a graphene grating. The gate voltage of graphene can regulate the nonreciprocal radiation intensity of the device in this article, without the need to resimulate the structure, and can achieve tunable strong nonreciprocal radiation effects. When the incident angle is 30°, the azimuth angle is 72° and the external magnetic field is 3 T, the thermal emitter can obtain strong nonreciprocal thermal radiation at a wavelength of about 16.6 μm. The difference between emissivity and absorptivity is greater than 0.91, indicating the presence of significant strong nonreciprocal radiation. We explained the physical background of this effect by studying the electromagnetic field distribution at the resonance peak.