The Research Of The Preparation Method Of Aluminium Back Junction N-type Silicon Solar Cells

The Photovoltaic(PV)industry has been growing rapidly in the past few decades as an important breakthrough in the construction of ecological civilization.More and more attention have been paid in researching on solar cells for its advantage in avoiding shortage of energy and environmental pollution.The conversion efficiency of solar cell can affect by not only the incident light intensity but also process and materials.The n-type silicon has been widely used in production,because the efficiency of solar cells carrier in n-type silicon is larger than that in p-type silicon,and the n-type silicon would not be affected by light-induced degradation of boron oxide complexes.Our work aims to researching the n-type silicon solar cells.We present the preparation and analysis of the aluminum back junction n-type silicon solar cells in this paper.Firstly,we simulated the solar cells with PC1 D software to create a ‘n+npp+’physical model.Secondly we analyzed the different factors that would affect the output characteristics of solar cells,such as the doping concentration near front surface,the recombination rate in the doping area,the resistivity of the substrate,the recombination rate near rear surface and the emitter depth of rear surface.Finally based on the simulation results,we found the main factors for optimizing the aluminum back junction n-type silicon solar cells and apply on the cell preparation process.We researched the influence of the rear surface morphology in the aluminum back junction solar cells and the weight of the Al paste for screen-printed systematically.We found that the polished-back surface is quite more efficient than the pyramidal-back surface.Meanwhile,more aluminum paste would be used to obtain higher efficiency under protecting the cells from bowing after printing.Then we analyzed the influence of front surface in the aluminum back junction n-type silicon solar cells.The optimal condition for front surface diffusion was used to producing the solar cells.In the end we compared the differences of passivation between monolayer SiNx-cell and double-layer SiO2/SiNx cell for further researching the passivation in the solar cells.We found that the electrical parameters of the double-layer samples improved dramaticallywith the open-circuit voltage reaching 637 mV after the passivation,obviously superior to the passivated monolayer SiNx samples.The efficiency of the optimized cells reached over 18.20%.