With the introduction of RbF (and CsF) post-deposition treatment (PDT) of CIGS absorbers, a step forward to even higher efficiencies could be made. Finally, using the RbF-PDT procedure combined with an advanced buffer system with very thin solution-grown CdS and sputtered (Zn,Mg)O, a certified cell efficiency of 22.6% (with anti-reflective coating) could be reached.
the EMPA (Swiss Federal Laboratories for Materials Science and Technology), the universities of Luxembourg (LU), Rouen (F), Parma (I) and Aalto (FIN), the IMEC (Interuniversitair Micro-Elektronica Centrum VZW in B), the HZB (Helmholtz-Zentrum Berlin für Materialien und Energie in D), the International Iberian Nanotechnology Laboratory INL (P), Flisom AG (CH), and Manz CIGS Technology GmbH (D). The idea behind this EU project is to pool these eleven organizations’ multidisciplinary skills in a bid to develop better cells.
The performance of thin-film solar cells based on chalcopyrite has improved markedly in recent years. Able to achieve 20.4 percent efficiency, CIGS solar cells on plastic foil are almost on par with multicrystalline solar cells. CIGS cells on glass topped that mark for the first time in 2013 and increased their lead by 1.3 percentage points to 21.7 percent in 2014. These two world records were achieved by two partners of the Sharc25 project: EMPA holds the record for the foil substrate and ZSW for glass.
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 641004.
European Sharc25 project aims to achieve 25 percent efficiency with thin-film solar cells
Sharc25, an acronym for ‘super high efficiency Cu(In, Ga)Se2 thin-film solar cells approaching 25%,’ aims to raise the bar even higher. The five research institutes, four universities and two companies are pursuing three strategies to achieve this goal: Improve the absorber material, harness the power of new designs for more efficient surfaces and interfaces, and optimize light management to raise the efficiency threshold another few notches. An increase of about three percentage points to 25 percent efficiency would be quite the leap in performance.