Micro-nano Optoelectronic Device Design And Related Characteristics Analysis

With the increasing integration of information technology,micro-nano optoelectronic devices have become a research hot spot in the field of optoelectronics with their advantages of low cost,high performance,and low energy consumption.The study of the structure and transmission characteristics of optoelectronic integrated devices or optoelectronic materials is a key research aspect of micro-nano optoelectronics technology,and has important impetus for the development of modern micro-nano optoelectronic devices.This paper focus on design and transmission characteristic analysis of micro-nano optoelectronic devices.By combining electromagnetic fundamental theory and numerical simulation methods,the spectrum properties are studied in asymmetric transmission devices,tunable metasurface devices and thin film solar cells,as well as the model design and working mechanism.The main results achieved are as follows:1.With the aid of spatially asymmetric coupling structures whose mode profield are matched in forward transmission,and mismatched in reverse direction,three structural design schemes are proposed to achieve asymmetric transmission with high unidirectional ratio in the field of on-chip integration.They are constructed by W2 waveguide/H1-type cavity/W2 waveguide based on square lattice dielectric-rod-type photonic crystal,W1 waveguide/modified-L 1 cavity/modified-W1 waveguide based on triangular lattice air-hole-type photonic crystal and W1 waveguide/modified-L3 cavity/modified-W1 waveguide based on triangular lattice air-hole-type photonic crystal,repectively.By numerical simulation of the finite element method,the proposed structures can achieve forward transmission efficiency peaks of 90%,79%,and 73%.The unidirectionality is close to 35dB,46dB and 37dB,respectively.In this design,the frequency selection characteristics can also be achieved by adjusting the structural parameters of the cavity which introduces degrees of freedom to adjust transmission efficiency spectrum.2.A novel metal-insulator-metal(MIM)structure with an adjustable-dielectric-constant conductive oxide is proposed for metasurface integrated color filters.The dielectric properties of the transparent conductive oxide(TCO)are used to adjust its dielectric constant to achieve epsilon-near-zero(ENZ)mode coupling.In this way,voltage modulation for the transmission spectrum is achieved for the first time.Numerical simulation results show that the proposed structure can achieve a high modulation ratio of more than 20dB for the transmission spectrum.3.The characteristics of carrier density distribution under voltage bias are studied for metal-insulator oxide-TCO(MOT)models with different materials.On this basis,the metal materials and TCO materials involved are applied to the metasurface periodic nano-antenna array,and the spectral characteristics of the antenna under voltage modulation are analyzed.The numerical simulation results show that the application of indium tin oxide(ITO)material to the active tunable metasurface antenna can achieve a reflection phase change exceeding 350°.4.To improve the efficiency of silicon-based thin-film solar cells,a considerable light trapping scheme is proposed for the anti-reflection layer and the back electrode.Firstly,for the front anti-reflection layer,the reflection characteristics of the two-dimensional grating structure and the three-dimensional semi-spindle structure are studied respectively;then,the optimal two-dimensional grating structure of anti-reflection layer is combined with the back electrode with trigonometric grating period structure,which is designed to construct the silicon-based thin film solar cell light trapping structure.Due to dielectric waveguide mode coupling and surface plasmon polariton(SPP)mode excitation,this structure can significantly improve the solar cell trapping performance.Through numerical simulations,compared to the referenced flat solar cell structure,the designed structure absorption efficiency and short-circuit current are improved by?10%and?8.2mA/cm2,respectively.