Why Topcon?

Compared to P-type crystalline silicon solar cells, N-type crystalline silicon solar cells have hig

h minority carrier lifeti

me, no light-induced degradation, good weak light response, and small temperature coefficient. They are the hope for the theoretical highest efficiency of crystalline silicon solar cells.

TOPCon is a solar cell technology based on the principle of selective carrier. It is a tunnel oxide passivated contact solar cell technology. The structure of the cell is an N-type silicon substrate solar cell, with an ultra-thin layer of silicon oxide on the back of the cell, followed by a layer of doped silicon. The two layers together form a passivated contact structure, effectively reducing surface recombination and contact recombination, providing greater space for the further impr

ovement of the conversion efficiency of N-PERT cells. The front of the TOPCon solar cell is no different from conventional N-type or N-PERT solar cells. The core technology of the cell is the back passivated contact. The back of the silicon wafer consists of an ultra-thin layer of silicon oxide (1-2nm) and a layer of phosphorus-doped microcrystalline/amorphous Si film. The passivation performance is activated through an annealing process, during which the crystallinity of the Si film changes from a mixture of microcrystalline and amorphous phases to polycrystalline. Annealing at a temperature of 850°C produces iVoc > 710 mV, J0 of 9-13 fA/cm2, demonstrating excellent passivation performance of the passivated co

ntact structure. The cell efficiency produced is more than 23%. Currently, the world record for N-type front surface passivated contact solar cells (25.8%) is held by the Fraunhofer-ISE research institute.

Advantages: 1. High cell conversion efficiency 2. Low light-induced degradation 3. High compatibility with process equipment production lines 4. N-type TOPCon cells can be combined with SE, IBC, multi-busbar, half-cut, and bifacial technologies to significantly improve cell efficiency and module power.