A thermal oxidation method for crystalline silicon solar cells

Abstract

The invention relates to the field of solar cells, A thermal oxidation method of crystalline silicon solar cell is disclosed, As to that nitrogen flow rate, oxygen flow rate, Pressure and temperatureare controlled in a specific step-by-step manner, A lay of uniform growth can be effectively grown on that surface of the crystalline silicon solar cell, The high quality SiO passivation film can repair the lattice defects and hanging bond defects on the surface of silicon wafer, redistribute the phosphorus diffusion curve on the surface of silicon wafer, reduce the ratio of phosphorus atom chemical concentration to available phosphorus atom concentration, prolong the minority carrier lifetime, and thus improve the conversion efficiency of silicon wafer.

Description

technical field [0001] The invention relates to the field of solar cells, in particular to a thermal oxidation method for crystalline silicon solar cells. Background technique [0002] With the development of crystalline silicon solar cell technology, good surface passivation has become an essential condition for the preparation of high-efficiency cells. Surface passivation is to reduce the surface activity of the semiconductor and reduce the recombination rate of the surface. The main way is to saturate the dangling bonds on the surface of the semiconductor, reduce the surface activity, increase the cleanliness of the surface, and avoid the formation of impurities due to the introduction of impurities in the surface layer. Recombination center, in order to reduce the surface recombination rate of minority carriers, so that the device works stably. [0003] The measures applicable to the surface passivation of solar cells generally include the following four aspects: surfac...

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Problems solved by technology

[0007] In order to solve the problems of uneven growth of SiO, poor surface lattice defects and dangling bond repair effect due to the slowdown of SIO growth on the surface of silicon wafer with the passage of oxidation time under the constant temperature and constant pressure state of the thermal oxidation process in the prior art, and the redistribution effect of phosphorus atoms Unsatisfactory, the problem that the conversion efficiency range of the final crystalline silicon cell is small, the present invention provides a thermal oxidation method for crystalline silicon solar cells, the method of the present invention adopts specific Step control can effectively grow a uniform and high-quality SiO passivation film on the surface of crystalline silicon solar cells, so that the lattice defects and dangling bond defects on the surface of the silicon wafer can be well repaired, and the phosphorus on the surface of the silicon wafer can be well repaired. The redistribution of the diffusion curve reduces the ratio of the chemical concentration of phosphorus atoms to the effective concentration of phosphorus atoms, improving the minority carrier lifetime, thereby improving the conversion efficiency of crystalline silicon cells

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