Research On Effect Of Seed Crystal And Doping On Polysilicon Materials And Its Photoelectric Properties

As a green renewable energy source,solar pv has a good development prospect and a larger proportion of China's energy structure.In recent years,the crystalline silicon solar cells in photovoltaic market dominant,so the preparation of high efficiency and low cost of crystalline silicon solar cell industry within the target of researchers for a long time.The conventional casting method of polysilicon mostly boron doped silicon crystal,because of the boron doped system based on boron oxide compound formed from becoming the center of the composite,resulting in a decline in the minority carrier lifetime,solar battery components of light attenuation is higher.With the development of photovoltaic technology,the quality requirements of the silicon chip are gradually improved,and how to reduce the later photoinduced attenuation becomes an urgent problem.Gallium doped silicon crystal instead of boron doped silicon crystals can avoid the formation of boron oxygen complex.Around these problems,this paper using directional solidification furnace G6 grow high efficiency crystalline silicon and gallium doped polysilicon efficiently,and the preparation and properties of silicon were studied systematically,the main innovations are as follows:(1)Studied different seed crystal type for efficient electrical properties of polycrystalline silicon,the influence of the research found that using particle size uniformity of seed crystal cast polysilicon grain size uniformity,particle material foundation of REC silicon ingot dislocation density is low,the effect is much better.Compared with the four seed crystal materials,the defect ratio of silicon chips cut after casting ingot with Siemens particle and REC particle is significantly lower than that of other two kinds of substrate materials,and the quality of silicon chips is higher,among which Siemens particle is better.Therefore,Siemens particles or REC particles can be selected as the seed crystal core layer in order to prepare more efficient and efficient polycrystals.The impurity content of ten metals,REC granule is obviously lower than the other three,Siemens particle has the lowest impurity content of five metals.The use of these two materials as the seed crystal nucleus layer is conducive to obtaining a relatively clean environment during nucleation,thus reducing the number of dislocation defects in the initial stage of crystal growth.(2)Battery performance of the gallium doped silicon ingot was studied,the study found that: the whole of the gallium doped silicon ingot ingot average cell conversion efficiency is not lower than that of boron doped silicon ingot,andillumination after the battery conversion efficiency is higher than that of boron doped silicon cells,significantly reduces the light to decay;Crystallization at the same height,gallium doped silicon ingot the resistivity distribution is uneven,and with the increase of height,liquid the doping concentration gradually increased,the solid liquid interface effect on the distribution of impurity is more obvious,lead to the inequality of the resistivity is more obvious;As a result of the gallium segregated coefficient is0.008,far less than 1,in gallium doped silicon ingot,with the increase of long jing height,has a wide distribution of longitudinal resistivity,resistivity is low head,but the resistivity distribution of silicon ingot tallies with the theories.The paper has a picture of 29,table 6,reference literature 139.