PERC Cell

PERC stands for Passivated Emitter and Rear Cell (sometimes Rear Contact). It is an enhancement to standard silicon solar cell architecture that adds a dielectric passivation layer to the rear surface of the cell, significantly boosting efficiency.

In a conventional solar cell, some light passes through the silicon wafer and is absorbed by the aluminum back contact, converting to heat instead of electricity. The PERC passivation layer reflects unabsorbed light back through the cell for a second pass, giving photons another chance to generate electron-hole pairs. This layer also reduces electron recombination at the rear surface, further improving energy capture.

These two improvements — internal reflection and reduced recombination — typically add 1% to 1.5% absolute efficiency over standard cell designs. Modern PERC cells routinely achieve 21% to 23% cell efficiency, making PERC the dominant cell technology in residential and commercial solar panels as of the mid-2020s.

PERC technology is compatible with both monocrystalline and polycrystalline silicon, though mono-PERC combinations deliver the highest efficiencies. The manufacturing process adds only a few steps to existing production lines, making it cost-effective to implement.

While newer technologies like TOPCon and HJT are beginning to surpass PERC in efficiency, PERC remains the price-performance leader for mainstream solar panel production.