Another world record for the most efficient multicrystalline silicon solar cell is claimed by Fraunhofer Institute for Solar Energy Systems (ISE) of Germany. Researchers produced a cell that converts 21.9% of incident sunlight into electricity.

The multicrystalline solar cell made of n-type silicon with an area of 2 cm x 2 cm. Photo: Fraunhofer ISEThe solar cell consists of n-type high-performance multicrystalline silicon, which demonstrates higher tolerance to iron and other impurities compared to p-type silicon. The record conversion efficiency was achieved by combining the n-type high performance multicrystalline silicon with Tunnel Oxide Passivated Contact (TOPCon) technology previously developed at Fraunhofer ISE.

TOPCon technology has metal contacts applied to the back side of wafers without patterning, which enables majority charge carriers to pass and prevents the minority carriers from recombining, boosting efficiency.

This technology was also used to achieve a record efficiency of 25.3 % in 2016 for a both-sides contacted monocrystalline silicon solar cell, indicating its suitability for both mono and multicrystalline silicon.