How are solar modules made?

We know that solar modules have a great influence on the development of solar energy, so how are solar modules made? Let's go take a look next. Look at the industrial production process of solar modules.

Here is the content list:

• Silicon material purification, crystal pulling or ingot casting, corner trimming of solar modules

• Slicing, cleaning, and texturing of solar modules, diffusion, and knotting

• Secondary cleaning, printing electrodes, and sintering of solar modules

  
  

Silicon material purification, crystal pulling or ingot casting, corner trimming of solar modules

The purification of silicon material for solar modules is to reduce high-purity silicon dioxide by reducing agent carbon to produce metallurgical-grade silicon with a purity of more than 98% and then purify it into solar-grade silicon with a purity of more than 99.99998% by the Siemens method (Purity requirements are lower than semiconductor-grade silicon).

The crystal pulling or ingot casting of solar modules is the high-purity silicon material obtained by the Czochralski method pulling and crystallizing into single crystal silicon rods, or the ingots are cast into polycrystalline silicon ingots of solar modules through quartz crucibles. The corner trimming process of solar modules is only suitable for single crystals, and the purpose is to grind the single crystal silicon rods of cylindrical solar modules into a nearly rectangular parallelepiped shape so that the cut out solar module silicon wafers is close to a square.

Slicing, cleaning, and texturing of solar modules, diffusion, and knotting

The slicing of solar modules is to use a multi-wire saw (diamond wire) to cut monocrystalline silicon rods or polycrystalline silicon ingots into 200-300μm thick slices. At present, the industry has used large-scale solar module silicon wafers of about 160-180μm for production. Solar module cleaning and texturing: firstly use lye (usually NaOH solution above 80 degrees Celsius) to corrode the damage to the silicon wafers of solar modules during mechanical processing, and then use lye (monocrystalline silicon wafer) or acid (polycrystalline silicon) respectively. Sheet) Prepare the suede surface of the solar module for anti-reflection, and finally spin the suede surface of the solar module with a spin dryer. Diffusion bonding of solar modules: The silicon wafers currently used in industry are mainly p-type wafers. Therefore, it is necessary to diffuse phosphorus (P) to form the junction of solar modules. The diffusion is generally carried out through a diffusion furnace, and the process temperature is higher than 900 degrees Celsius, but A low-temperature diffusion process is currently being developed. If you use n-type wafers to prepare solar modules, you need to diffuse boron (B).

Secondary cleaning, printing electrodes, and sintering of solar modules

The secondary cleaning of solar modules is because inactive phosphosilicate glass is formed during the diffusion process, so the solar modules need to be corroded by hydrofluoric acid (HF). The anti-reflection film of the solar module is prepared by plasma-enhanced chemical vapor deposition in the industry to prepare the anti-reflection film of the solar module of silicon nitride SiNx. The printed electrode of the solar module is prepared by screen printing the front and rear electrodes of the solar module. The front electrode of the solar module is generally made of silver paste, the rear electrode of the solar module is made of silver aluminum paste, and the backfield of the solar module is printed with aluminum paste. The printed electrodes of solar modules have the advantages of being quite fast and low cost, and there are also several patents on the market. The sintering of solar modules is high-temperature sintering in a sintering furnace so that the front electrode of the solar module burns through the silicon nitride anti-reflection film on the front surface, the n-type layer forms a good ohmic contact, and the aluminum on the back of the solar module diffuses into the silicon, A p+ heavily doped area is formed on the back surface to form the back surface field of the solar module.

To produce and make better solar modules, the manufacturer of Anhui JF Solar Technology Co., Ltd. (JF Solar) pays great attention to solar modules, has injected a lot of investment, and has achieved many excellent results. If you are interested in solar modules, you can contact us, our website is https://www.jf-solartech.com/.