A Optical Coaxial Ultrasonic Spray Laser Doping System

Abstract

The invention discloses a light external coaxial ultrasonic spraying laser doping system which comprises a stander and also comprises a laser emission head and an ultrasonic atomization nozzle for spraying a doping source subjected to ultrasonic atomization, wherein at least one ultrasonic atomization nozzle is arranged on the stander; the laser emission head and the ultrasonic atomization nozzle are closely arranged and are positioned above a silicon slice to be processed, so that laser emitted by the laser emission head forms a laser light spot region on the surface of the silicon slice to be processed, and the doping source sprayed by the ultrasonic atomization nozzle is gathered on the laser light spot region to realize laser heating and doping source scattering. The light external coaxial ultrasonic spraying laser doping system can realize synchronous doping, namely the laser heating and the doping source scattering can be simultaneously realized; a doping source coating working procedure and a laser scanning working procedure in the prior art are synchronously finished, and the technical steps are simplified; moreover, the system is simple in structure, low in equipment cost and low in production cost.

Description

technical field [0001] The invention belongs to the technical field of laser doping of crystalline silicon solar cells, and in particular relates to a laser doping system that provides a doping source in an ultrasonic spraying manner. Background technique [0002] As solar energy becomes an increasingly viable clean energy, improving the conversion efficiency of solar cells and reducing manufacturing costs have become the focus of the solar cell industry. Selective emitter structure is currently one of the effective ways to improve the conversion efficiency of solar cells. By heavily doping the semiconductor emitter region, a good ohmic contact can be formed between the semiconductor and the metal. However, heavy doping increases the Auger recombination and reduces the quantum efficiency in the short-wavelength region of sunlight. In order to avoid these disadvantages, a selective emitter structure is proposed: (i) heavy doping is realized directly under the battery metal ...

AI Technical Summary

Problems solved by technology

For spin-coating doping, each silicon wafer needs to be placed on a spin-coating machine. In industrial scale production, multiple spin-coating machines are required to work at the same time. After the silicon wafers are spin-coated and doped, they are taken and placed on the assembly line. Laser scanning, therefore, requires corresponding silicon wafer pick-and-place devices (such as robotic arms) and dopant source drop devices during the spin-coating doping process, which is not only expensive but also complex in process, which is not conducive to pipeline production; for dopant source deposition methods In terms of vacuum coating equipment, it is necessary to use vacuum coating equipment, that is, to place silicon wafers in vacuum coating equipment for vacuum deposition of dopant sources, and then take them out and place them on the assembly line for laser scanning. This also increases production steps and improves cost of production

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