IMEC has presented a large-area cell (125cm2) at the European Photovoltaic Solar Energy Conference that incorporates a shallow emitter and advanced front metallization using copper plating instead of silver, which has a conversion efficiency of 18.4%. IMEC plans to develop the technology to efficiencies above 20% and wafer thickness of 40µm.
“Using copper instead of silver adds to the sustainability of solar cell production,” remarked Dr. Joachim John, team manager at IMEC. “IMEC was able to do this because it has extensive experience with copper plating on silicon. A similar efficiency result was obtained with screen printed contacts, but the long-term sustainability and low-cost potential of Cu-based contacting solutions and the fact that this was a first result obtained without dedicated fine-tuning makes this result particularly encouraging.”
“These cells and the new metallization stack involved are a further successful step in IMEC’s target to develop ever more cost-effective, efficient crystalline Si solar cells – eventually targeting cells that are only 40µm thick with efficiencies above 20%,” commented Dr. Jef Poortmans, IMEC’s Photovoltaics Program Director.
IMEC noted that the shallow emitter results in an enhanced blue response, and thus in a higher conversion efficiency than with a standard emitter. The front contacts used a novel metallization stack is added which is applied to local openings in the antireflective coating.
Caption: IMEC’s i-PERC cell with shallow emitter and Cu metallization