Research On Selective Diffusion And Surface Passivation For Crystalline Silicon Solar Cell

It is described that the innovatory technology of selective diffusion and study on surface passivation in theory for crystalline silicon solar cell.Firstly, the basic principle of solar cell is summarized ; secondly, the study on selective diffusion for crystalline silicon solar cell is introduced ,including the explain away structure of selective emitter solar cell and the technological design of selective diffusion; at last, the research of surface passivation in theory is expounded.As far as the new technology of selective diffusion, the method of printing is used and the phosphoric paste (high concentration) is printed at the electrode-site in silicon. Afterwards, A thin layer of phosphoric source (low concentration) is sprayed on the surface of the non-electrode-site in silicon.The result is showed that the value of square resistence is 30.2 O in heavily doping area and 100.2O in lightly doping area . In the heavily doping area, high surface concentration (1020/cm3 above) and relatively deep junction depth (0.52um) in silicon is taken form. In the lightly doping area, low concentration (1019/cm3 below) and relatively shallow junction depth(0.45um) is obtained. Therefore, the selective diffusion is brought about successfully.The PC ID has been used in order to analyse the influence of surface recombination on the performance of crystalline silicon solar cell. In different surface concentration, the relation of the surface recombination velocity and the performance(Voc,JSc,g) of crystalline silicon solar cell is discussed. It is essential that the surface concentration of solar cell is not more than 5X1019/cm3 and the surface recombination velocity of it is 104cm/s below to obtain ideal performance of solar cell.