Phosphorus washing solution for crystalline silicon solar battery, manufacturing method and use method thereof

Abstract

The invention relates to a phosphorus washing solution for a crystalline silicon solar battery. The phosphorus washing solution is composed of hydrogen fluoride (HF) and deionized water; a surface active agent is added in the hydrogen fluoride (HF); the three components of the phosphorus washing solution and the weight ratio thereof are presented as follows: 7%-15% of the hydrogen fluoride (HF), 5-100ppm of the surface active agent and 85%-95% of the deionized water. A manufacturing method of the phosphorus washing solution comprises the following steps: adding the deionized water into a container; slowly adding the hydrogen fluoride (HF) and the surface active agent; and stirring for 5-10 minutes till completely dissolving. A use method of the phosphorus washing solution comprises the following steps: soaking a silicon wafer with residual impurities on surface into the phosphorus washing solution at normal temperature, and after soaking for 1-3 minutes, washing the silicon wafer with a hydrochloric acid and then washing with the deionized water. The phosphorus washing solution disclosed by the invention can be used for efficiently treating phosphorosilicate glass (PSG) and impurities spread on the surface of the silicon wafer, thereby causing the surface of the silicon wafer to be cleaner and obviously promoting electrical performance of the solar battery.

Description

technical field [0001] The present invention relates to a chemical solution and its production and use method, more specifically, to a phosphorus washing solution for removing phosphosilicate glass on the silicon chip surface of a crystalline silicon solar cell and its production and use method. Background technique [0002] During the production process of crystalline silicon solar cells, after the diffusion process, POCL 3 with O 2 P 2 o 5 deposited on the silicon wafer surface. P 2 o 5 React with Si to form SiO 2 and phosphorus atoms, so that a layer of SiO containing phosphorus is formed on the surface of the silicon wafer 2 , called phosphosilicate glass. This layer of material will affect the incidence of sunlight, and will also reduce the contact performance between the surface of the silicon wafer and the electrode. At the same time, this layer of material has a certain gettering effect. Phosphorus atoms form the impurity source on the surface and absorb Fe a...

AI Technical Summary

Problems solved by technology

However, it can be observed through a high-power electron microscope that this method cannot completely remove the phosphosilicate glass on the surface of the silicon wafer, and there are still residues of phosphosilicate glass impurities on the surface of the silicon wafer, and the existence of this residue will still affect the electrical performance of the battery.