Draining current from the wafer requires many small holes in the non-conductive layer to allow the metal electrode to contact the silicon wafer. The LFC process enables nearly 100,000 contact points on the wafer to establish a connection with a single laser pointer pulse.
The biggest difficulty of this work is that the laser pulse can form a good contact with the silicon surface and reduce the damage to the material. The most important point is that the effect of the laser must be limited to 50-2000 nanoseconds, the doctor explained. The innovative system they developed can guide the laser beam to optimize the energy density distribution in a time of close to 1 second.
Solar cells use this method to increase the efficiency level of 1% absolute value. According to the conversion efficiency of solar cells close to 20% today, this is approximately equivalent to a relative value of 5%. We have increased by an additional 2% in this system, which means we have increased our total energy output by 7%, said the doctor.
The level of efficiency is critical, because most photovoltaic costs are directly proportional to the surface area. “Today we need 100 square meters of solar cells, so in the future we only need 93 square meters to generate the same amount of electricity. This not only means that the use of silicon is reduced, but also the module materials are reduced. The reduction in the amount of materials in the system can reduce cost
Solar cell manufacturers can easily and cost-effectively integrate green laser pointer processes in existing production processes. According to company information, Hanwha Q Solar Cell Company has produced 20 million batteries using LFC technology. Many companies in the world have put PERC technology into mass production. “This year alone, manufacturers have invested 200 million euros to implement this technology. This means that silicon solar cells have entered the next revolutionary stage,” Ralf Preu said with excitement.
They have received the 2016 Joseph von Fraunhofer Prize for their status as initiators and drivers of changes in solar energy technology. The jury attributed their reason for the award to “The technology developed by the researchers helps German companies continue to succeed in the highly competitive photovoltaic market.