PERC – P-TYPE
PASSIVATED EMITTER AND REAR CELL
Traditional solar cells contain two layers of silicon, commonly called “n-type” and “p-type” for their negative and positive charge behavior. The difference between N-type and P-type semiconductors is the primary material used to create the chemical reaction during doping.
The term p-type refers to the fact that the cell is built on a positively charged (hence p-type) silicon base. Indeed, the wafer is doped with Gallium, which has one electron less than silicium. P-type solar cells proved to be more resistant to space radiation and degradation.
PERC cell technology aimed to achieve higher energy conversion efficiency by adding a dielectric passivation layer on the rear of the cell. Because this extra layer is reflective, it is able to send unused light back across the n-type and p-type junctions to generate more energy. Thus, in PERC Cells, the front surface absorbs sunlight while the rear surface absorbs scattered or reflective light.
PERC CELL TECHNOLOGY I STRUCTURE
Passivated Emitter and Rear Cell
One of the biggest reasons why PERC technology can be so powerful is the minimal investment it takes to begin manufacturing PERC solar cells instead of standard monocrystalline solar cells. In order to produce a PERC cell, there are two additional manufacturing steps needed:
- Application of the back surface passivation layer
- Laser/chemical etching to open small pockets in the passivation layer
These two steps don’t add significant costs to the solar cell manufacturing process and result in a higher quality, more energy-dense solar cell and more value to the customers.