Ultra wideband solar capture devices based on GaAs and Ti metasurface

Abstract

In this paper, a multilayer composite structure based on GaAs, Si and Ti materials is designed, which is composed of threedimensional nested geometric elements. The wide-band resonant absorption of the structure is realized by multiple mechanisms. The surface plasmon resonance (SPR) excited by the interface between Ti layer and semiconductor localized and dissipated the light energy on the metal surface. The Fabry Perot cavity resonance formed by multi-layer superposition enhanced and extended the light propagation path through different wavelength standing waves. The dielectric interference and multimode coupling caused by the refractive index difference between GaAs and Si layers further enhanced the absorption effect. In terms of thermal radiation, the emissivity of the structure reaches 96.0% at 1200 K, and the radiation efficiency reaches more than 90% in the range of 800-1400 K. The enhancement of high density optical states (LDOS) caused by the metal semiconductor interface effectively promotes the release of thermal radiation energy. The finite-difference time-domain (FDTD) method was used to calculate the value. The average absorption rate of the absorber was 94.74% in the range of 280 nm-3000 nm, and the bandwidth was 2684 nm. The absorption rate was higher than 93% when the incident angle increased to 50 ° and 88.7% when the incident angle increased to 60 °.