Research On Moth Eye Antireflective Metasurface In Multiple Wavelengths Of Visible,Near-infrared And Mid-infrared

Moth eye anti-reflection micro-nanostructure has gradually become a hot research topic because of its wide application in optical windows,display devices and solar cells.The requirements of broadband,wide angle and environmental adaptability have become the key indicator for the moth eye anti-reflection devices with the development of theory and preparation technology.In this paper,the rigorous coupled wave and finite difference time domain method are used as the theoretical basis.Si and multispectral ZnS moth eye structures are optimized by FDTD-Solutions which applied to the incident angle 0°⁶0°range of 2⁵ microns infrared wide spectrum and 0.41⁵ microns visible,near ang middle infrared super wide spectrum.The effect of wavelength and incident angle on the anti-reflection performance is studied by simulation with the change of morphological parameters.Based on the simulation results,the Si and the ZnS moth eye structures are fabricated by laser interference lithography,magnetron sputtering and inductively coupled plasma etching.The relationship with the exposure dose and the size of photoresist mask is analyzed during photolithography.On the other hand,the relationship with etching gas ratio and etching time is analyzed during inductively coupled plasma etching.The optical and mechanical properties of the prepared samples are tested and analyzed.The test results show that the wide-spectrum and wide-angle anti-reflection performance of silicon moth eye structure are improved by 29%³6%compared with the bare structure,but the damage resistance of moth eye structure decreases.The wide-spectrum and wide-angle anti-reflection performance of ZnS moth eye structure are improved by 26%³3%compared with bare structure,and it has relatively good damage resistance.The mechanical properties of Si moth eye are improved by depositing Al₂O₃ film.Without reducing the anti-reflection performance,the damage resistance of Si moth eye structure is improved which can satisfy the application requirements of optical window.