Bionic Fabrication Of Super-hydrophobic And Low-reflection Surfaces On Silicon Substrate

There are some problems of solar cells, such as the difficulty in focusing absorption ofincident sunlight, the lower conversion efficiency caused by overheating, the poor stabilityaffected by abominable environments. Natural organisms have a good adaptability indifferent environments. Some specific structures of plants and animals directly contribute tothe characteristics of optical propagation control, temperature control and self-cleaning. Inthis study, we take some special structure of the organisms as the bionic object and carryout a brief survey on the bionic mechanism and preparation technologies of the intelligentmulti-function solar cell surface structure. We have proposed two kinds of experimentscheme based on the structure principle, test optical properties, hydrophobicity andmicro-geometry to verify the multi-function characteristics. The main contents andconclusions are listed in the following.1) Some organisms have perfect characteristics of hydrophobic and anti-reflection, andthe ordered microscopic structures on the surface play a decisive role. Nanowire/polestructures have an important effect on the capabilities of the decontamination for theorganisms, while the similar nanowire/pole structures may show excellent opticalanti-reflection for another organism. Therefore, we possibly get combined characteristics ofhydrophobic and anti-reflection by adjusting the distribution and the scale of thenanowire/pole. And such silicon structures would bring in a significant breakthrough toimprove efficiency and self-cleaning activity, the if they are used as a semiconductormaterials in solar cells.2) We use a wet chemical etching method to fabricate silicon nanowire arrays andmeasure the morphology, hydrophobicity, optical properties of the structures.In theexperiments, we use the monocrystalline silicon(100) and fabricate large-area siliconnanowire arrays by a wet chemical etching method at room temperature. Using this methodbased on the galvanic cell reaction, SiNW arrays have been realized by chemically depositingAg nanoparticles on silicon wafers in aqueous HF+AgNO3mixed etching solution at roomtemperature. In the test of these silicon wafers, silicon wafer surfaces consisting silicon nanowire arrays show the characteristics of low-reflection less than5%in the450-790nmwavelength range and super-hydrophobicity with a high water contact angle up to150.3) We find the wet chemical etching method has a poor reproducibility andcontrollability. In this study, we get a research in the method of mask assisted etchingnanostructures at the same time, and discuss the self-assemble technology of SiO2nanoparticles. At last we successfully obtain SiO2nanoparticles nano-particle monolayer, andit is useful to fabricate nanostructures.