At the 25th European Photovoltaic Solar Energy Conference (Valencia, Spain),
imec presents several large-area
silicon solar cells with a conversion efficiency above 19%. Two types of cells
were realized namely with Ag-screenprinted contacts and plated Cu-contacts.
Efficiencies of cells with screenprinted contacts were up to 19.1% whereas
19.4% was obtained with Cu-plated contacts. These high efficiencies were obtained
thanks to several factors amongst which a combination of improved texturization
and optimized firing conditions. The results were achieved on large-area cells
(148cm2) with 170µm thickness, proving the industrial viability of the
process.
Imec’s Cu-plated large-area silicon solar cell with 19.4% efficiency.
Imec’s record efficiency silicon solar cells feature rear-side passivation,
laser ablation and, local aluminum back-side field and screenprinted contacts
or Cu-plated contacts on advanced emitter schemes. “The fact that such
efficiencies can be obtained by metallization schemes based on screenprinted
Ag contacts enables compatibility with present industrial metallization practice
in the solar cell industry. The Cu-based front-side metallization is a step
towards higher sustainability and lower cost, substituting Ag with Cu in future
industrial production of crystalline silicon solar cells;” said Dr. Joachim
John, team manager industrial solar cells at imec. “These exciting results
were obtained in the new solar cell process facilities recently set up in imec.”
“High efficiency, low cost, and sustainability are the main drivers in
imec’s research on crystalline silicon solar cells, eventually targeting
cells that are only 40µm thick with efficiencies above 20. We expect further
improvements towards efficiencies of up to 20% for large-area silicon solar
cells. This achievement is a major step forward towards industrial manufacturing
of sustainable, low-cost, thin silicon solar cells with high efficiency,”
said Dr. Jef Poortmans, director imec energy/solar program.
The results were achieved within imec’s silicon solar cell industrial
affiliation program (IIAP), a multi-partner R&D program that explores and
develops advanced process technologies aiming a sharp reduction in silicon use,
whilst increasing cell efficiency and hence further lowering substantially the
cost per Watt peak.