Preparation And Application Of Gallium Arsenide Optical Resonant Nanoarray

Resonant nanostructures are widely used to fabricate effective anti-reflective coatings due to the characteristics of directional scattered light.With the rapid development of nanoarray structure fabrication process,the absorption in specific wavelengths can be enhanced by fabricating a resonant nanostructure on the surface of materials.The"light management"is widely used in the field of optoelectronics.Gallium arsenide?GaAs?photocathodes have been widely studied as negative electron affinity photocathode materials due to their high sensitivity,resolution and signal-noise ratio.By fabricating an optical resonant nanostructure on the surface of the device,the array structure as an active area,it can greatly increase the light absorption rate of the active area and reduce the transport distance of photoelectrons.The shape,size,distribution and optical constants of nanostructures are important parameters affecting their optical resonance characteristics.How to accurately control these parameters to obtain the resonant optical regulation effect that meets the requirements of practical applications is the main technical difficulty that needs to be solved today.In this paper,GaAs optical resonance nanostructure model was established by FDTD,and reasonable boundary conditions were obtained to obtain a suitable size nanoarray structure with resonance effect.Then nanoimprint technology and SiO₂ nanosphere self-assembly method were used for etching mask on GaAs surface.The substrate was then etched by ICP to obtain the GaAs optical resonant nanostructure.The optical properties of the results were tested and analyzed.Finally,we obtained an optical resonant nanostructure with a minimum reflectance of 5%.The fabrication of nanoarray structure was mainly divided into four parts.The first part is to prepare the array mask layer by Nanoimprinting,and the SiO2 array mask layer was obtained.The second part is the SiO₂ nanosphere self-assembly method to prepare the array mask layer.Firstly,the monodisperse SiO₂nanospheres were prepared by St?ber method.The target particle size SiO₂ nanospheres were prepared after analyzing the influence of reaction time on the synthesis of nanospheres.Then,the nanosphere films were prepared by spin coating,vertical deposition and gas-liquid interface respectively.By analyzing the influence of the hydrophilicity of the GaAs surface and the mass fraction of the nanosphere on the spin coating method,the influence of temperature on the vertical deposition method and the influence of the mass fraction of the nanosphere on the gas-liquid interface method,a closely arranged monolayer SiO₂nanosphere was obtained.The third part is to prepare the nanoarray by etching GaAs with the prepared mask layer as an etch mask,and the bias power and N₂ were studied in the GaAs etching.The optimum parameter is used to prepare a GaAs nanoarray with good surface morphology,and finally verify its optical resonance characteristics through micro-area optical reflection test.The nanostructures provide the basis for the application of the optical resonator in the field of optoelectronic.