Crystalline silicon solar battery selective diffusion process

Abstract

The invention belongs to the technical field of crystalline silicon solar battery preparation, in particular to a crystalline silicon solar battery selective diffusion process. The crystalline silicon solar battery selective diffusion process with simple process and low cost comprises the steps of concentrated phosphor diffusion, phosphorosilicate glass removal, printing corrosive agent etching and corrosive agent cleaning and removal. The solar battery prepared by the process has shallow emitter junctions with good surface passivation effect, high short wave effect can be obtained, at the same time, the battery obtains good ohmic contact because of the heavy doping in a grid line region, higher battery conversion efficiency can be obtained, and in addition, the process steps are simple. Compared with the traditional process, the invention needs to add less equipment.

Description

technical field [0001] The invention belongs to the technical field of preparation of crystalline silicon solar cells, and in particular relates to a selective diffusion process of crystalline silicon solar cells. Background technique [0002] At present, the solar cell diffusion process tends to prepare shallow junctions to obtain good short-wave photoresponse, but shallow doping will greatly reduce the contact performance of printed electrodes. To form a good ohmic contact, in addition to improving the performance of electrode paste, it must be done under the electrode. Heavy doping, that is, forming a highly doped deep diffusion region under and near the electrode gate line, and forming a low doped shallow diffusion region in other regions, so how to achieve shallow doping and heavy doping in different regions has become a problem currently encountered. to the problem. At present, high-efficiency batteries in laboratories basically use selective emitters, such as PERL ba...

AI Technical Summary

Problems solved by technology

At present, high-efficiency batteries in laboratories basically use selective emitters, such as PERL batteries, PERT batteries, buried gate batteries, etc., and there are two main methods for preparing selective emitters: one is to use a silicon dioxide layer mask The process steps are: silicon wafer cleaning and texturing → high temperature oxidation → printing corrosive slurry etching → slurry cleaning and removal → 30 ohm concentrated phosphorus diffusion → oxide layer removal → 80 ohm light phosphorus diffusion → edge etching and washing Phosphorus, due to the need to increase multi-step high-temperature processes and equipment, the mass production process is cumbersome, the production efficiency is low, and the cost is high. What is important is that multiple high-temperature thermal processes will have adverse effects on the performance of silicon wafers, such as the decrease in the minority carrier lifetime, The silicon wafer becomes brittle, etc.; the second is to use photolithography or laser method, but due to the high cost, it only stays at the laboratory level

In addition, it has also been reported that the selective emitter electrode was prepared by screen printing phosphate slurry, which is suitable for industrial production, but due to the technical obstacles in the preparation of phosphate slurry, it has not been applied on a large scale, thus limiting its industrialization