Key points on PERC cells:
- PERC solar cells are generally more efficient and resistant to heat than traditional silicon crystal cells.
- Using PERC cells in solar panels can increase their average efficiency from around 18% to over 21%.
- PERC solar cells are still subject to some of the same limitations as traditional solar cells.
There are a lot of developments worth paying attention to in the solar industry, but few have made as big of a splash as PERC solar cells. These cells are the next step in solar technology evolution, offering improved efficiency and performance under stressful conditions.
We created this guide to PERC solar cells to help you understand this exciting emerging technology. You’ll learn how they work, how they’re different from traditional cells, and what advantages they can offer you for your solar energy setup.
What is passivated emitter rear cell (PERC) solar technology?
PERC is a high-efficiency solar technology. It adds a dielectric layer to silicon cells. This layer reflects light and reduces recombination. The result is better light trapping and higher power conversion efficiency (PCE).
In effect, panels outfitted with PERC photovoltaic cells generate more energy than traditional panels of the same size under the same conditions.
How do PERC cells compare to traditional options?
Monocrystalline and polycrystalline cells are standard silicon-based PV technologies. Both can use PERC cells, and these are known as mono PERC and poly PERC. Mono PERC offers the highest performance, while poly PERC is a cost-effective upgrade over traditional polycrystalline panels.
Conventional monocrystalline and polycrystalline solar cell design
Traditional monocrystalline and polycrystalline solar cells are made with a layered construction that includes the following components:
- Front contact: Collects electrical currents produced in the cell
- Anti-reflective coating: Helps trap and absorb sunlight
- N-type silicon layer: Top layer of the cell where sunlight enters
- P-type silicon layer: Bottom layer that completes the diode
- Back contact: Closes the cell and collects electrical currents
This design encourages electron movement when sunlight hits the cell. Photons excite electrons, creating electron-hole pairs. The cell’s electric field drives electrons toward the n-layer and holes to the p-layer. Electrons flow through an external circuit, generating usable electricity to power your home.
Mono PERC and poly PERC solar cell design
The architecture of PERC cells is basically the same as conventional cells, with a few important distinctions. The key differences are:
- Dielectric Passivation Layer: A thin rear coating of aluminum oxide (Al₂O₃) or silicon nitride (SiNx) minimizes carrier recombination and enhances light trapping by reflecting unabsorbed photons.
- Laser Contact Openings (LCO): Precision laser ablation creates micro-openings in the passivation layer. This creates rear-side electrical contact without compromising insulation.
- Rear Metal Contact: Improves charge collection and ups solar efficiency by reducing energy losses from carrier recombination.
How do PERC panels increase solar efficiency?
Based on industry research, PERC solar cells tend to increase solar cell efficiency by 1 to 1.5%. This is a more significant boost than it may sound like at first. As a result of this improved efficiency, PERC solar cells can increase the solar panel efficiency—or, the amount of sunlight converted to energy—from around 18% to 21%.
PERC boosts efficiency through two mechanisms:
- Rear surface passivation: PERC cells reduce electron recombination losses, increasing the amount of electrons that can contribute to energy creation.
- Light trapping: The dielectric layer in PERC cells reflects infrared light that is lost in traditional panels. This gives photons in sunlight a second chance at stimulating electron activity.
Are PERC cells more expensive?
Yes, PERC cells are typically more expensive than standard monocrystalline or polycrystalline cells. This is because they take more time and resources to manufacture.
That said, PERC cells offer better energy yield per square foot, which can lower your system’s levelized cost of electricity (LCOE) over time. For many, the long-term savings and performance gains justify the upfront cost.
Why use PERC PV modules?
PERC solar cells are ideal for residential rooftops, commercial buildings, and utility-scale solar farms. Their high efficiency makes them perfect for limited space. Strong performance in heat and shade suits diverse environments and improves the energy yield you can get.
Below are a few main benefits.
Higher energy yields
PERC cells can create more energy under the same conditions as traditional cells. This makes them more efficient overall, but even more useful in low-light, cloudy, or angled-light conditions.
Better temperature coefficients
Solar panels with PERC cells also perform better in high-temperature environments, which are unfavorable to the efficiency of traditional cells.
Lower levelized cost of electricity (LCOE)
The superior efficiency of PERC solar cells means that they can produce more electricity per unit area, reducing the per-kWh cost of the system.
What are the downsides to PERC solar cell architecture?
While PERC solar cells are indeed a breakthrough in solar technology, they still have some weaknesses. These include:
Light-induced degradation (LID)
All solar panels suffer a gradual loss in efficiency over time due to sunlight exposure, including those with PERC cells. Treatments like gallium doping can help reduce LID.
Potential induced degradation (PID)
Like other solar cells, PERC cells are also subject to efficiency loss from leaking “stray” currents. Improved encapsulation materials and design, plus better grounding systems, can help reduce the effects of PID.
Heat accumulation
The rear layer in PERC cells traps more light than traditional solar cells, which can increase the temperature of the cell and reduce efficiency and longevity.
Who manufactures PERC solar cells?
Top PERC solar cell manufacturers like LONGi, JA Solar, and JinkoSolar offer high-efficiency PV modules for residential and utility applications. Manufacturers use a combination of bifacial cells, light-trapping layers, and laser contact openings in various products.
| Manufacturer | Technology Highlights | Primary Markets | Notable Features |
|---|---|---|---|
| LONGi Solar | Mono PERC, bifacial, rear surface passivation | Residential, utility-scale | Industry leader in mono-PERC with strong R&D backing |
| JA Solar | Mono PERC, bifacial PERC modules | Commercial, residential | Offers both standard and bifacial PERC modules |
| Trina Solar | PERC, TOPCon hybrid technology | Utility-scale, large commercial | Pioneering integration of PERC with other architectures |
| JinkoSolar | PERC, laser contact opening (LCO) tech | Residential, solar farms | Known for innovation in rear surface field (RSF) design |
| Canadian Solar | Mono PERC, bifacial, light-trapping design | Residential, industrial | Strong North American presence, solar module supplier |
Variants and evolving competitors to PERC solar technology
While PERC solar cells are quickly gaining ground in the industry, they aren’t the only emerging solar technology in development. There are a few other types of solar cells being researched for commercial production. Some of the other developing technologies include:
Tunnel oxide passivated contact (TOPCon)
These cells are a more advanced form of PERC solar cells that offer superior passivation and contact quality.
Heterojunction technology (HJT)
This newer type of solar cell combines crystalline and amorphous silicon layers to increase power output.
Bifacial PERC
This construction allows PERC cells to capture energy from both front and rear sides, resulting in even greater solar efficiency.
Bottom line on PERC solar cell technology
PERC solar cells are an exciting area of development for the solar industry. While they don’t solve all the problems inherent to traditional crystalline panels, they offer the promise of more efficient panels and the potential for lower startup costs in the future. As more research goes into the development and manufacturing of PERC cells, you can expect to see more and more of them on the market.
Learn more about solar from PowerOutage.us
At PowerOutage.us, we monitor real-time power disruptions for over 150 million U.S. customers using data from 900+ utilities. Trusted by news outlets and emergency agencies since 2016, we create educational content to help homeowners understand technologies like solar energy that improve power resilience and independence.
This article is part of our expert series on solar panel technology, which also includes:
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Taking your time to research is important, because solar panels aren’t always best for every situation.
