Opening a new era of photovoltaic cells-TOPCon solar cell

TOPCon solar cell (Tunnel Oxide Passivated Contact) is a solar cell that uses an ultra-thin oxide layer as the passivation layer structure. It concept was first reported at the 28th EU-PVSEC in 2013 by Dr. Frank Feldmann of the Fraunhofer Institute in Germany .TOPCon cells are designed to improve solar cell efficiency by solving the cell carrier selection passivating contact problem.The TOPCon solar cell is a tunneling oxide layer passivation contact technology developed on the basis of the N-type solar cell process, which can significantly improve the VOC (open circuit voltage of PV modules) and conversion efficiency of N-type solar cell.

TOPCon solar panels have proven to take the bifacial factor up to 85%. So the Bifacial Solar Panels can increase power gains by up to 2%.The core advantages of TOPCon solar cell mainly include two aspects, one is the high theoretical conversion efficiency ceiling, which is based on POLO2-BJ structure, TOPCon theoretical efficiency of 28.7%, close to the limit of crystalline silicon; second is based on the existing PERC production line upgrade, 60% of domestic PERC production capacity can be transformed into TOPCon. Therefore, in the face of massive depreciation accrual of old PERC line, transformation into TOPCon solar cells can lengthen the equipment application cycle and reduce the risk of sinking, which is a better choice.It is worth mentioning that TOPCon solar cells can be manufactured as n-type or p-type solar cells, but the n-type variation has proven to be more efficient and resistant to impurities.

Up to now,there are about 67 domestic companies planning to layout TOPCon soalr cell production lines in China, among which there are about 22 new market players entering PV cells, and about 42 companies are expected to be completed and successfully put into operation this year. There are 12 companies with capacity plans over 30GW. With an eye on the capacity progress in 2023, the monthly annual capacity of TOPCon solar cells was 54.3GW in January and 74.9GW at the end of March this year, and it is expected that the monthly annual capacity will reach 517.6GW in December after the projects are put into operation this year.