Microlens Array Antireflection Film And Its Application In Solar Cells

Solar energy is considered one of the most promising renewable energy sources due to its advantages in alleviating the current energy crisis and environmental pollution.Solar cells can directly convert solar energy into electricity through photoelectric conversion,but they are not widely used at present.The main reasons are that the production cost of solar cells is too high and the conversion efficiency is too low.Therefore,in the future research,improving the conversion efficiency and reducing the cost of solar cells is the main goal of the research.The application of nano-micro structure anti-reflection film can greatly reduce the reflection of light on the front surface of the battery,so as to improve the photoelectric conversion efficiency of solar cells.Therefore,in the solar photovoltaic industry,it is of great significance to study and apply micro-nano structure anti-reflection film.In this paper,the micro-nano structure anti-reflection film of solar cell is taken as the research object,and the anti-reflection film of biomimetic puffer skin nano-pricking polymer is improved and designed from the aspects of morphology and preparation method,and the process method of preparing anti-reflection film by combining template replication and polydimethylsiloxane(PDMS) contraction is also developed.The optical subtraction and electrical properties of the obtained experimental samples were studied.The main research contents and results of this paper are as follows:First,we designed the bionic benzene-ring DSNT structure by using Finite-difference time-domain method(FDTD) method,and produced it by non-contact and non-mask direct laser engraving photolithography process.By adjusting the laser power,the upper surface reflection of crystalline silicon solar cells can be reduced to maximize the height of DSNT.The epoxy DSNT film was transferred from the photoresist template to the surface of the planar Si substrate by soft embossing.Interestingly,we found that the DSNT structure maintained mechanical integrity during the transfer process and did not undergo significant deformation to destroy the original optical properties of the DSNT structure.The reflectivity of DSNT films with benzene ring epoxy resin was studied in the wavelength range of 300-1100 nm.The DSNT film of benzene ring epoxy resin significantly reduces the surface reflection of silicon substrate.In addition to the anti-reflection property,we found that the epoxy resin DSNT film has hydrophobic and self-cleaning ability.Therefore,adding epoxy DSNT film to the top of the crystalline silicon solar cell can effectively reduce the reflection of its upper surface.In addition,according to the consistent photoelectric characteristics measured in the experiment,the epoxy resin DSNT film can significantly inhibit the upper surface reflection loss of crystalline silicon solar cells,thus significantly improving photoelectric conversion efficiency(PCE).Therefore,the epoxy resin DSNT film can be a good choice for reducing the upper surface reflection loss of optoelectronic devices at present.Second,in order to simplify the fabrication process of antireflective film for crystalline silicon solar cells,we propose a preparation method of antireflective film with low reflection loss.Hexagonal dense row micron-column array templates were prepared by laser direct writing lithography.Micron-structured pattern templates were copied onto pre-stretched transparent PDMS films.After stress release,PDMS shrinkage reduced the period of micron-structured pattern and increased the depth-width ratio.The experimental results show that compared with the film with unshrunk micron structure,the shrinking film reduces the reflectivity of the solar cell from 15.5% to 13.24%,the relative reflectivity decreases by 17.1%,and the relative photoelectric conversion efficiency of the solar cell increases by 5.51%.In addition,the prepared PDMS film can improve the hydrophobicity and self-cleaning ability of the solar cell surface.