PV Cell Technology

TOPCON- N- Type

TUNNEL OXIDE PASSIVATED CONTACT

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.

An N-type solar cell consists of a thin p-type silicon (doped with boron) layer over a much thicker n-type silicon (doped with phosphorus) layer. Electrical contacts are applied to both sides. N-Type solar cells offer lower temperature coefficients, better operating temperatures, and better LID degradation, leading to all around improved power generation.

Tunnel oxide passivated contact (TOPCon) solar cell technology is a new development with the eventually to replace passivated emitter and rear contact (PERC) and high-efficiency passivated emitter, rear totally diffused (PERT) solar panels.

TOPCON has an N-Type Silicon substrate and a thin tunneling oxide is applied, followed by a layer of highly doped with n or p poly silicon that contacts the metal at the ends. These tunneling oxide blocks one type of carrier and thus they are called passivating contacts.

TOPCON CELL TECHNOLOGY I STRUCTURE

The processes and existing equipment that are commonly used in the manufacturing of PERC cells may be easily adapted to TOPCon cell production by adding two process steps:

The formation of tunnel oxide.
The deposition of intrinsic/doped polysilicon.

To manufacture TOPCon cells, tunnel oxide, and polysilicon layers are added to the rear side of the cell. It helps the cell handle higher voltages, which increases power production.

TOPCon Cell Technology I Benefits

TOPCon cells convert more sunlight that P-type cells, which results in a higher cell and module efficiency.

The temperature coefficient is the percentage of power output lost by a PV Module for each degree of temperature increase. It impacts the power generation of PV modules in hot conditions.

TOPCon solar cells have a lower power degradation power during the 1st year and during the 30 years of PV panels use.

TOPCon cells have a better resistance to high temperatures, which means the efficiency of TOPCon modules will be higher.

TOPCon cells have a better power increase in bifacial modules than other technologies.

TOPcon solar cells have a higher efficiency in low light condition, which extends the electricity generation period during the day and improves the performance of the installation over time.