Imec announces 22.5% efficiency for n-type PERT solar cell
Solar cell. Author: Michael Dorausch michaeldorausch.com License: Creative Commons
Belgian nanotechnology research centre Imec today said it has reached 22.5% conversion efficiency for a n-type PERT (passivated emitter, rear totally diffused) solar cell.
The result, presented at Intersolar Europe, is the highest efficiency recorded so far for a two-side-contacted solar cell processed on 6-inch (15.24 cm x 15.24 cm) commercially available n-type Czochralski silicon (Cz-Si) wafers, without the use of passivated contacts, Imec said.
In a drive to boost the conversion efficiency of n-type silicon solar cells, Imec is exploring material and architectural improvements to extend its n-PERT concept. The cells feature Ni/Cu/Ag front contacts, rear local contacts, a diffused front surface field (FSF) and a rear emitter. They have reached an open-circuit voltage (Voc) of 689 mV, a short-circuit current (Jsc) of 40.3 mA per sq cm, and 80.9% fill factor (FF).
Imec has also been working on n-type PERT cells with a rear side p-type emitter using epitaxial growth or heterojunction processes. These advanced architectures have come near 22% conversion efficiency.
“We have a strong commitment to continue increasing the efficiency our n-PERT technology, and are very optimistic that these achievements will further pave the way to industrialization in the near term,” said Filip Duerinckx, manager of Imec’s n-PERT technology platform.
N-type silicon solar cells are seen as promising alternatives to p-type solar cells for next generation highly efficient solar cells due to their ability to withstand light-induced degradation and their higher tolerance to common metal impurities, the research centre explained.