centrotherm photovoltaics’ centaurus technology for high efficiency solar cells

At this year’s 6th International Solar Industry and Photovoltaic Exhibition & Conference in Shanghai (SNEC), centrotherm photovoltaics AG focuses on the successful ramp-up of centaurus high efficiency cell production at customers in China and Europe. As a highlight, centrotherm offers live measurements of
centaurus cells to the fair audience and thus demonstrates constant cell efficiency in mass production.

“Almost on a weekly basis, lab results of efficiency world records are reported. Yet, the crucial figures are those in mass production,” commented Dr. Peter Fath, CTO of centrotherm photovoltaics AG. “By now, around 100.000 cells have been processed with centaurus technology - the majority at our Chinese pilot customer, who has already reached efficiencies of more than 19.5% in industrial-scale production on a daily average, and even up to 19.8% at its peak. These figures once more substantiate our technology leadership.”

centaurus technology combines the one-step selective emitter technology with a local Al- BSF and dielectric passivated rear side. Compared to present standard industrial solar cells with extensive screen printed Al-BSF, centaurus cells show considerably reduced ear surface recombination velocity with increased Voc of more than 10 mV and an improvement of internal light reflection for long wavelengths leading to a gain in Jsc of about 1.5 mA/cm². Both effects are claimed to lead to an overall efficiency improvement of about one percentage point, allowing average production efficiencies of more than 19.5 %. Along with fine line printing, reducing paste consumption of the front side silver paste by more than 20 %, we already achieved conversion efficiencies reaching the 20 %
level on 156x156mm² monocrystalline (cz) wafers.

Currently, more than 50MW of centaurus technology are in ramp-up into mass production. Further existing customers have already expressed great interest in
implementing this technology. Its advantage is the availability for mass production at the same cost level as the standard process. Compared to other passivated rear side concepts, it is based on well proven processes and materials, allowing a fast and easy implementation into running production lines.
“We are pursuing the goal that our customers strengthen their position as premium cost leaders. Thanks to our regular upgrade packages they have the ability to apply state-ofthe- art technology in the long run”, commented Dr. Peter Fath.