Design And Application Of Microstructures With Enhanced Utilization Of Photons

Solar energy is a kind of green and sustainable new energy with a wide range of sources,and has broad space for development and application.Solar cells are devices that can directly convert the energy of the sun’s rays into electrical energy,and have important research and application value.However,commercial solar cells are not efficient,resulting in high cost of photovoltaic power generation.Therefore,improving the optical absorption and utilization of solar cells and enhancing the efficiency of solar cells is a very important issue.The plasmonic metal nanostructures,silicon nanostructures,and dielectric nanostructures have unique scattering properties,and can be effectively regulated according to their structure,morphology,and size,and have potential applications in the field of enhancing photon utilization efficiency of solar cells.In addition,using a high transmittance,high conductivity surface plasmonic metal nanowire transparent conductive film as a window electrode can improve the performance of the solar cell device at the same time in terms of optical absorption and carrier collection efficiency and has high research value.The scattering properties of the surface plasmonic silver nanostructures and silver-silicon composite nanostructures were studied and analyzed,and I applied them to solar cells to explore their properties of enhancing solar cell light absorption.In addition,the research on transparent conductive thin films of inexpensive copper nanowires(Cu NWs)available for solar cells has been conducted.Two methods are used to attempt to solve the problem of poor oxidation resistance of copper nanowires.First,a highly stable and highly disperse oily nanowire ink is prepared;second,a copper-silver core-shell nanowires(Cu@Ag NWs)coated with a silver shell is used.The main innovations obtained in this paper are as follows:(1)A silver particle with a diameter of 400 nm and a rough surface was designed.This lumpy particle has a broad spectral extinction ability,uniform local electric field distribution,and excellent backscattering ability.I optimized the coverage density of 400 nm lumpy Ag particles embedded in the rear of crystalline silicon thin film solar cells,and found that 20%is the best.After introducing nano-texturing on the silicon upper and lower interfaces,the short-circuit current density of the solar cell can be increased by 15.1%.The above-mentioned 400 nm silver particles with a rough surface were prepared experimentally.By adjusting the reaction parameters,the average diameter can be effectively controlled in the range of200-700 nm without changing the surface morphology of the particles.(2)A composite light scattering nanostructure with strongly scattering silver nanocones and absorption medium silicon nanopillars was designed.By adjusting the period of the silver-silicon composite structure array,zero reflection at certain wavelengths can be achieved.(3)A highly stable and highly disperse copper nanowire ink was explored,and the influence of the concentration change of the main components of the ink on the ink performance was studied.Through simple parameter adjustment,it may develop into a universal ink formulation.From the nanowire ink,a transparent conductive film can be prepared by a simple method,and the conductive film has excellent light transmittance and conductivity.(4)Inventively developed a method for preparing a copper-silver core-shell structure with a completely covered and uniform morphology.The existence of a complete silver shell will provides anti-oxidation protection for the copper nanowire matrix without affecting its transparency and conductivity,which will bring cheap copper-based nanowires transparent conductive film a wide range of application prospects.