How Photovoltaic Modules Are Designed and Produced?

1. From silicon material to silicon wafer

To put it simply, it is to slice a large piece of silicon material. The technology involved is not complicated. The main pain point is the localization of production equipment. The production process of silicon wafers is similar to that of chip wafers, but the accuracy requirements of wafers are higher. High, the requirements for silicon wafers are simple and rude.

2. From silicon wafer to cell

The production process of various technical routes is different. Taking the current mainstream monocrystalline silicon PERC cell production process as an example, the process from silicon wafer to cell is roughly as follows:

1>. Texturing: make the surface of the silicon wafer rough and reduce the reflectivity

2>. Diffusion: Brush a layer of phosphorus to form a PN junction

3>. Etching & edge insulation: remove the PN junction on the side surface to prevent short circuit

4>. Back passivation: This is the most important step for PERC cells. Through back passivation, the transmission of light is reduced, thereby improving the photoelectric conversion rate.

5>. Coating: silicon nitride film to reduce reflection and protect the battery from corrosion, etc.

6>. Screen printing: printing metal electrodes

7>. Sintering: sintering electrodes and silicon wafers

8>. Sorting: sorting batteries with different efficiencies

3. From cell to module

At present, LONGi, which has the largest market value in the A-share photovoltaic sector, is to make modules. The functions of photovoltaic module components are as follows:

Photovoltaic glass: protect the cells from corrosion and increase the service life of the cells.

EVA film: bonding battery and photovoltaic glass, battery and back film.

Back film: insulation, moisture-proof, anti-ultraviolet, airtight, anti-aging, anti-corrosion.

Frame: protect components, connect installation.

Junction box: lead out the bus bar.