Antireflective Microstructure Design And Electrical Property Research Of Silicon Based Solar Cell

Energy shortage and environment deterioration are the two main problems that hinder the sustainable development of human society. The demand of energy can be satisfied adequately without any environment destruction if solar energy which is both clean and renewable can be utilized high efficiently. Photovoltaic energy industry has been one of the most rapidly developed industries in the world. Solar cell is the core part of photovoltaic technology. Silicon based solar cell dominates the solar cell market relying on its advantages of stable performance, high efficiency and abundance of material origin. Therefore, to improve the conversion efficiency of silicon based solar cell is of great importance. Since optical loss and electrical loss are the two main reasons that affect silicon based solar cell’s efficiency, two parts of research work are carried out in this paper respectively.As regards the optical loss on the front surface of cell, the anti-reflection properties of silicon based solar cell with parabolic cone array structure is studied in this paper. Parameters of structure that influence the anti-reflection performance, such as the height of parabolic cone array, the period and the duty factor are analyzed by using of finite-difference time-domain method. The analysis shows that the reflectivity tends to reduce as the height and duty factor of structure increase.According to the simulation result, less than 3% reflectivity can be achieved in the whole response spectrum of silicon solar cell(wavelength from 300 nm to 1200nm) for5 groups of parameters, i.e. the base diameter of parabolic cone is 128 nm, 160 nm,213nm, 256 nm, 320 nm respectively, with the array’s height of 600 nm and the period of array equal to the base diameter. Three types of optimized structures based on parabolic cone are also proposed, which reduce the reflectivity to only 1% and exhibit excellent antireflective performance in the case of oblique incidence as well. Our work provides a novel design approach for an anti-reflective surface of the silicon based solar cells. Moreover, the height of microstructures designed in this paper is only 600 nm, which is helpful to reduce the cell thickness and material cost.In the aspect of electrical loss of silicon based solar cell, research is also carried out accordingly. Parameters that affect the properties of solar cell, such as doping density, reflectivity of front surface and series resistance, are studied by using solar cell simulation software PC1 D. The reason of the simulation results are also analyzed.Based on those work, an optimized design of monocrystalline silicon solar cell is proposed. The conversion efficiency of commercial monocyrstalline silicon solar cell before optimization is 17.29%. After optimization, the conversion efficiency achieves as high as 22.14%.