The solar industry is experiencing a wave of innovation that is transforming the way we harness energy from the sun. As the demand for renewable energy grows, researchers and manufacturers are developing new technologies that enhance the efficiency of solar panels. One such technology is TOPCon Solar cells.

TOPCon (Tunnel Oxide Passivated Contact) solar technology is an advanced type of photovoltaic cell designed to improve the efficiency and performance of solar panels. It is an upgraded version of PERC (Passivated Emitter and Rear Cell) solar cells, which are widely used today. TOPCon cells use a thin layer of Tunnel oxide (Fig 1) between the silicon wafer and the metal contacts. This layer reduces energy loss by improving the movement of electrical charges within the solar cell.

TOPCon solar cell layers
Fig 1 : TOPCon solar cell layers

How does a TOPCon solar cell work?

TOPCon solar cells work on the principle of passivation to reduce the energy loss. In normal solar cells, some energy is lost as heat or through imperfection on the surface of silicon wafers. TOPCon technology addresses this by adding a very thin layer of silicon oxide which acts like a tunnel for electrons. This layer blocks the passage of a charge carrier(Fig 2), but is thin enough to allow electrons to flow more efficiently while minimizing the energy loss caused by recombination. Recombination loss occurs when electrons and holes cancel out each other.   

Charge carrier passage blocking
Fig 2 : Charge carrier passage blocking

How is TOPCon Different from other solar modules?

Compared to traditional solar technologies like PERC or standard silicon cells, TOPCon stands out in several ways:

  1. Higher Efficiency: TOPCon solar cells are more efficient because they reduce energy loss and improve charge transfer efficiency. Current TOPCon solar modules typically achieve efficiencies of 22 % to 24 %, whereas PERC solar modules usually range between 20% to 22%.
  2. Improved performance in low light: TOPCon cells perform better under low-light conditions, such as cloudy weather or early morning and evening.
  3. Better temperature coefficient: TOPCon cells maintain theory efficiency better in high temperature environments, where traditional cells can lose their performance at high temperature.
  4. Durability and Longevity: TOPCon cells have a longer Lifespan and a lower degradation rate compared to other technologies.

What is the Life of TOPCon Solar Module?

TOPCon Lifespan is typically around 25 to 30 years, making them a long term investment for clean energy generation. The degradation rate is also lower than the conventional solar panels, averaging about 0.4% per year. This means, after 25 years, a TOPCon solar panel can still produce around 80 to 90 % of its original power output compared to 80 to 85 % for traditional solar panels. TOPCon technology is a significant step forward in the solar industry because it combines high efficiency, durability, and cost-effectiveness. While it is slightly more expensive to manufacture than standard solar panels, its higher energy output and longer lifespan can offset the initial cost, making it an excellent choice for residential, commercial, and utility-scale solar installations.

While writing this article I got an opportunity to visit the manufacturing facility of Rayzon Solar. They are at the forefront of solar technology with their TOPCon solar panels(Fig 3).

TOPCon 210R Solar Module
Fig 3 : TOPCon 210R Solar Module

Rayzon solar has an impressive 4 GW production capacity, driven by automated technologies that significantly enhance the operational efficiency while upholding the highest standard of quality.

Advanced Manufacturing technology
Fig 4 : Advanced Manufacturing technology

Rayzon Solar’s R&D and testing facility are impressive. Solar module manufacturers are supposed to test their panels for Mechanical Load Testing, Light and elevated Temperature Induced Degradation (LeTID), Potential Induced Degradation (PID), and Damp Heat Testing. The photograph below (Fig 5) shows their testing facility for the TOPCon modules. Such intensive testing makes sure that the modules have a longer lifespan.

Testing Facility
Fig 5 : Testing facility of Rayzon

I hope you now have a better understanding about TOPCon solar cell. To explore more about solar energy please check out our detailed course on solar power production. Thank you.