A Study On Self-assembled Nanostructures Based Surface Anti-reflection Properties

With advances in technology and the rising sense of saving energy,high-performance renewable new energy and energy-saving new light sources have been being seeking.Solar Cells and light-emitting diodes(LEDs),in those applications,are widely employed.Photoelectric devices,such as solar cells and LEDs,relying on light as the medium,are composed of multi-layer dielectric materials.The reflection loss at the interface,therefore,has become an unavoidable problem.Nanostructures are widely used in optoelectronic devices because of their excellent antireflection and omnidirectional properties.However,due to its characteristic size in the nanometer scale and the high cost of lithography technology preparation,the utilization of nanostructures in optoelectronic devices is limited.At this time,the self-assembly technology with simple operation,low cost and large-area preparation of nanostructures has become an excellent alternative technology for the preparation of nanostructures.In this paper,the surface optical anti-reflection of LEDs and silicon-based Solar Cells based on self-assembled triangular lattice nanostructures is studied.The main research contents and achievements are as follows:(1)An analysis of the working principle of LEDs based on P-GaN strictly periodic triangularly-arranged nanostructures was carried out.Building theoretical models is the first step.By analyzing the different geometric parameters of the nanostructure,the influence mechanism of different geometric shapes is explored.The simulation results show that the radiation mode of LED changes and the light extraction efficiency are significantly enhanced after the introduction of triangular lattice nanostructure.Compared with planar LED,the light extraction efficiency of parabolic nanostructured LED is increased by 48.74%,under the optimal structure parameters with the period of 0.7μm,the height of 0.15μm and the fill factor of 0.1.(2)The anti-reflection properties of the surface triangularly-arranged cup-shaped nanostructured silicon wafers based on self-assembled AAO were investigated.The cup-shaped nanostructured silicon arrays were prepared on the surface of silicon wafer by self-assembly technology,transfer AAO template,thermal evaporation metal aluminum mask column,dry etching and other processes.Compared with the reflectivity of planar silicon,the anti-reflection ability of silicon with this nanostructure is improved.The reflectivity of silicon wafer with nanostructure array on the surface is lower than 25%in the wavelength range of 250-2500nm.(3)On the basis of the above,the cup-shaped nanostructure is further pushed to the silicon-based Solar Cells,and the influence of the surface cup-shaped nanostructure on the light absorption ability of the silicon-based Solar Cell is simulated.The results show that the surface cup-shaped nanostructures do have high light-harvesting performance,and under the optimal structural parameters,the maximum Jph of Solar Cell can reach 31.19m A/cm~2,which is superior to other sidewall profile nanostructures.