Font Size: a A A

Fabrication Optimization Of Silicon Micro-nano Structures By Metal-Assisted Chemical Etching

Posted on:2022-02-20Degree:MasterType:Thesis
Country:ChinaCandidate:S Q YuFull Text:PDF
GTID:2491306482486464Subject:Environmental Engineering
Abstract/Summary:PDF Full Text Request
The continuous development of the global society has accelerated the dependence of human beings on energy,the traditional energy is constantly being consumed,and various extreme climates caused by energy consumption pollution need to be improved.Finding a renewable green energy to gradually replace traditional energy becomes an urgent need.Silicon solar cells are widely used due to their environmental friendliness and high stability.However,the high-cost of the high-purity monocrystalline silicon materials and the low conversion efficiency of amorphous,polycrystalline silicon has seriously hindered the development of silicon solar cells in the photovoltaic industry.The new silicon micro-nano structure has the advantages of low cost and light trapping effect,which is an effective way to improve the photovoltaic performance of silicon-based solar cells and reduce the cost.The morphological quality of silicon micro-nano structure is directly related to its fabrication process.In order to reduce costs and simplify the process as much as possible,the most commonly used fabrication in laboratories is the MACE method with the template.Although the template method has developed and matured,its process operation is still relatively complex.To this end,we use the self-precipitable K2SiF6 crystal combined with MACE method as an alternative to the traditional template method to systematically study the influence of various conditions on the structure of silicon micropillars during the experiment.The main research work is as follows:A template-free,low-cost fabrication was proposed.This technology combines the self-nucleated K2SiF6 crystal and MACE method to produce silicon micro-nano structure.This method successfully achieved a large area and uniform silicon micropillar structure,which greatly reduces the difficulty of process operation.Electron microscope and X-ray spectrometer were used to detect the elemental composition and morphological characteristics of K2SiF6,and it was confirmed that K2SiF6 particles are the most critical factor in the preparation of micro-pillar structure using this technology.The formation mechanism of silicon micropillar structures in KMnO4-HF-AgNO3 etching solution was proposed,and the micro-pillar structure’s micro-evolution was described by changing the etching time.The effect of corrosion time and etchant composition on the morphology and overall distribution of silicon micropillars was systematically studied,silicon nanowires were also investigated in this work.The relationship between the morphology and reflectance of the micropillars prepared under various conditions was analyzed,moreover,it was found that the condition of 0.05M KMnO4-9.8 M HF-0.03M AgNO3 reached the best optical performance,and the light reflectance under this condition is as low as 12.63%.Sodium dodecyl sulfate(SDS)surfactant was selected to optimize the fabrication process.A densely arranged vertical silicon micropillar arrays were successfully achieved on the entire 2×2cm2 silicon wafer.The influence of the addition of SDS on the morphology of the silicon micron pillars was explored.The addition of 1 mg of SDS greatly increased the density of the silicon micropillar arrays,and the single micropillar was fabricated completely without over-etching,and plenty of short silicon nanowires were fabricated.the aspect ratio of it is up to 2.22.From the perspective of crystal nucleation,the effect of the addition of SDS in the formation of silicon micropillars was studied.As a surfactant,SDS directly affects the interfacial energy in the solution,thereby affecting the formation of K2SiF6 crystals.The influence of etching time and the concentration of each component of the etchant on the morphology of the micropillar arrays was systematically analyzed.The absorbance of experimental conditions was investigated.The addition of HCl reagent was put forward as an additional factor affecting the synthesis of silicon micro-nano structures.Based on this,the silicon micropillar structure with an angular surface was achieved.The surface of the structure is smooth and the overall distribution is relatively uniform.The influence of HCl addition amount on the structure of micron column was studied,and 0.5ml was selected as the ideal HCl addition amount for fabricating higher density silicon micropillar structures.The morphology evolution of silicon micropillar structure with the change of etching time and the concentration of various etchant components under the condition of adding HCl was systematically studied.The absorbance spectra of experimental conditions were illustrated.
Keywords/Search Tags:Silicon micropillar, antireflection, Metal-Assisted Chemical Etching, Sodium dodecyl sulfate
PDF Full Text Request
Related items