The Design Of Antireflection Structure On Silicon Solar Cells And The Research Of Influence Of Ag-Cu Nanoparticles On Positive Electrode Preparation

With the energy crisis becoming more and more severe,the reserves of traditional fossil energy cannot come up with the developing industry.People focus their attention on the green and renewable energy,which includes the potential solar energy.Due to their mature production and preparation technology,and low manufacturing cost,crystalline silicon solar cells have already been in mass production in the industry.For for higher efficiency and lower preparation cost,the paper improve the solar cells in two aspects: Firstly,to decrease the reflection,increase the absorption and improve the efficiency of solar energy,we design a double antireflection structure on monocrystalline and multicrystalline silicon wafer surface;Secondly,to improve the contact properties of the silicon and positive electrode prepared by screen-printed method,we add Ag-Cu nanoparticles into the paste.After firing,the silicon solar cell is manufacture completely.The paper propose several conclusions as follows:(1)we prepared the textured structure by chemical method.As for monocrystalline silicon,the textured surface prepared by acid solution presented a pyramid structure,while the textured multicrystalline surface prepared by alkali solution presented a porous structure.Then,a thin Ag film was evaporated on the textured surface by electron beam evaporation and annealing process.We then used reactive ion etching to manufacture the nanorods structure.This kind of double antireflection structure can lead the incident light to secondary or triple or quartic reflection,which can improve the absorption efficiency.The average reflectance between 460-800 nm of the textured structure on monocrystalline silicon was decreased to 11.98%,while for the polystalline silicon,it can be decreased from 31.12% to 15.27%.The experiment explored out the best conditions of preparing Ag particle mask,which included the thickness of Ag film,the annealing temperature and annealing time.The height of prepared nanorods were 700-800 nm.We found that the average reflectance of monocrystalline silicon possessed this double antireflection structure can be decreased to 5.28%,while the 12.98% for the polystalline silicon.(2)We prepared positive electrode of polystalline silicon solar cells with screen-printed method,also we explore the best annealing process of the positive electrode.We found that when adding 10 wt.% Ag-Cu nanoparticles,the conversion efficiency can be improved to 6.06% from 5.85% in our experiment.We used x-ray photoelectron spectrometer to test the composition in the interface between the electrode and silicon.It was found that the content of Ag conductive metal in the interface was higher than that on the surface.And by scanning electron microscope,we found re-precipitated metal particles in the interface.The we came up to the mechanism that Ag-Cu nanoparticles can improve the conversion efficiency of solar cells.