Study on nonreciprocal radiation and photothermal conversion of VO2-based tunable inverse opal thermal emitter

Abstract

In this work, a novel tunable nonreciprocal thermal emitter, consisting of an InAs magneto-optic inverse opal film and a VO2 film, is designed to achieve strong and tunable nonreciprocal radiation in the mid-infrared band of 6.8–7.8 μm. A more appropriate Lorentz-Drude model is used to describe the material properties of InAs, and the nonreciprocal band in the mid-infrared range for doped InAs is obtained through the Lorentz-Drude model. The effect of different middle layers on the structure of films and inverse opals is investigated under a magnetic field at an incident angle of 26° The inverse opal structure is found to have better nonreciprocal properties, while VO2 has the role of replacing noble metals in the tuning of nonreciprocal radiation. In addition, the strengthening mechanism of the inverse opal structure and the physical mechanism of the nonreciprocal radiation are further analysed and revealed through electric field energy distribution plots and impedance matching theory. A comparison of the nonreciprocal radiation and the photothermal effect of three inverse opal structures with different pore distributions and porosities for different parameters shows that the simple cubic structure has the strongest nonreciprocal radiation performance and a relatively high photothermal conversion effect, which can further increase the radiation capacity of the thermal emitter over a range. Therefore, the designed inverse opal composite structure can be used for the fabrication of tunable thermal emitters with nonreciprocal effects, where the amount of light absorbed in one channel of the thermal emitter can be controlled to tune the radiation capacity of the other channel. Providing a degree of assistance in the development and application of nonreciprocal thermal radiation devices in the mid-infrared wavelength band.