Pressemitteilung BoxID: 731019 (SCHMID Group | Gebr. SCHMID GmbH)
  • SCHMID Group | Gebr. SCHMID GmbH
  • Robert-Bosch-Str. 32-36
  • 72250 Freudenstadt
  • Ansprechpartner
  • Sarah Kreidler
  • +49 (7441) 538-326

Light-induced degradation in case of multi-crystalline, rear side passivated solar cells (PERC)

Comparison of PERC and PERT cells shows clear advantages of the PERT technology / Since the light-induced degradation fails to appear, PERT cells offer a better performance than PERC cells at the same manufacturing cost

(PresseBox) (Freudenstadt, ) With its innovative APCVD systems the SCHMID Group offers the possibility of PERT (Passivated Emitter Rear Totally Diffused) cell production. According to recent studies, they offer significant performance benefits in the field compared to PERC (Passivated Emitter and Rear Contact) cells, since PERT cells do not show the considerably light-induced degradation documented for PERC mc-cells.

Amongst others the study "Light Induced Degradation of Rear Passivated mc-Si Solar Cells" by K. Ramspeck et al., published on the occasion of the 27th EU PVSEC, shows the following: Multicrystalline solar cells that are passivated with aluminum oxide Al2O3 (PERC) on the rear side, show a degradation of up to 6% (relative) with respect to standard mc-BSF cells, when being exposed to light. Obviously the degradation effect is basically different from the light-induced degradation in Cz-cells and cannot be regenerated either.

Based on the findings on the light-induced degradation of PERC cells, the SCHMID group has developed systems for the production of PERT cells that are proven to have no degradation effect, at the same manufacturing costs as for PERC cells. Another advantage of SCHMID's PERT technology is that the cells can be used in conventional modular technique with backsheet as well as for bifacial use. The PV industry appreciates this technology innovation and this is why SCHMID has already been able to sell several systems for the production of PERT cells.

The new PERT process technology is primarily based on the APCVD (Atmospheric Pressure Chemical Vapor Deposition) systems developed by SCHMID. Working at atmospheric pressure and using chemical vapor deposition these systems guarantee a consistent coating quality at a high throughput and at low cost. APCVD systems are therefore the most effective way to apply the required number of layers, which are required for modern high-performance solar cells.

For more than 10 years the SCHMID APCVD systems have already been used in industry with great success and high acceptance, and are continuously improved in the SCHMID own technology centers and adapted to future trends - such as bifacial and PERT cell concepts.