The Preparation And Antireflection Effect Of Microstructure On Photovoltaic Cell Surface

Scientific research personnel do a lot of significative work for improving sunlight high-usage by degrading the reflected light of solar cells surface. Usually, antireflections adopt a quarter-wave way in industrialization. Further more, solar cells surface are deposited antireflectived thin film. But there are some defects in the method such as the coefficient of thermal expansion of the different materials is unmatched; the adhesive force is too bad and so on. So now, some research personnel apply themselves to research the antireflection of surface microstructures. In this paper, the quasi-period surface microstructure of the nano-holes, micro-spike and nano-grass were preparation by means of metal-assisted chemical etching, femtosecond laser inducing and ICP etching for making the antireflectived microstructures by the efficient method. On the different conditions, the morphological change and mechanism of the light trapping microstructure were researched, and that the surface microstructures would maybe applied in photoelectric sensor, microelectronics device and Solar PV field were analyzed exploringly. Finally, the principal results of this thesis were listed as follows.1,Base on the mean of metal-assisted chemical etching, a series of the different scales nanoholes were fabricated. After the method the conditions and parameters were optimized, the super light trapping surfaces were obtained between 300 to 1000nm range. By the research on the concentration, temperature, thick of Ag film and etching time of the corrosive liquid, the optimal technological parameter were obtained. By the optical fiber spectrometer, the reflectivity of the nano-holes surface was investigated. Finally, the nano-porous silicon was applied in solar cell were discussed exploringly.2,By the mean of femtosecond laser inducing silicon in SF6, the micro-spike structure was fabricated successfully. The laser parameters toward the effect on the morphology of the spikes were investigated. And the optimal parameters were obtained aim at the micro-spikes surface. By the UV-VIS spectrophotometer, the micro-structure surface reflectivity was measured.3,By the mean of ICP etching the nano-grass structure was fabricated successfully. The gas rate of flow, etching time, RF power and work pressures toward the effect on the silicon grass preparation were investigated, and the definite parameters were summarized. By the optical fiber spectrometer, the reflectivity of the different scales silicon grass surface was investigated.4,The size, density and homogenization of Ag nanoparticles on Si substrate were adjusted through high temperature metal film annealing. And the annealing time, temperature and initial film thickness were investigated by the numbers. The better exciting SPR conditions for the fabrication of the uniform, small and high density transition metal catalyst nanoparticles on Si substrates are as follows:the etching duration of about 10min, the temperature of 900℃and initial film thickness of 10nm.5,The mechanism of a micro-primary battery based on the contact reaction between mental nanoparticles and Si has been verified. In view of the mechanism, the model of forming porous structure by precious metal particles assisted etching was established. Based on the geometric optical transmission mode, the model of light trapping on the porous structure surface was proposed. According to the wave-particle dualism of light, the properties of multiple reflection and absorption of light in the holes structure were establish, and the reason that porous structure has antireflection properties were verified.6,Comparing with different background environment Si surface micro-structure induced by femtosecond laser inducing, the whole process of forming periodic surface micro-tapered structure in the SF6 atmosphere were verified, and built geometric optical model of surface antireflection properties which belongs to micro-spikes structure. A kind of new material applied by photoelectronic device was provided.7,Based on Maxwell electromagnetic field theory, equivalent medium model was applied to make clear antireflection properties on silicon grass surface. The model shows surface periodic micro-structure can contribute to the great increase of broadband light trapping uniformity and optical antireflection properties.