CZTSe Solar Cells Achieve 9.7% Efficiency

A copper zinc tin selenide (CZTSe)-based solar cell has achieved 9.7 percent efficiency, bringing the solar industry a step closer to a sustainable alternative to CIGS-based solar cells, its creators say.

The thin-film technology was fabricated by scientists at imomec, the associated lab of imec at Hasselt University, and by the European R&D consortium Solliance. The sputtering of the Cu, Zn and Sn metal layers was performed at Flamac in Ghent, and glass manufacturer AGC provided the molybdenum-on-glass substrates and subsequent annealing in a H2Se-containing atmosphere. The resulting polycrystalline absorber layers were 1 µm thick.

The thin-film CZTSe solar cell developed by scientist at imec, imomec and Solliance has achieved 9.7 percent efficiency. Courtesy of imec.

The samples were processed into solar cells using a standard flow for thin-film solar cells at Helmholtz Zentrum Berlin and finished with a metal grid and antireflective coating at imec. The highest efficiency obtained for the 1 × 1 cm² cell was 9.7 percent, with a maximum short-circuit current of 38.9 mA/cm², an open circuit voltage of 0.41 V and a fill factor of 61 percent.

“This is a big win for us. We’ve been working toward this milestone since 2011, when we first started our research on alternative materials for thin-film photovoltaics at imec/imomec,” said Marc Meuris, program manager of the alternative thin-film PV program at Solliance. “Our efficiencies are the highest in Europe and approaching the world record for this type of thin-film solar cells, and we look forward to further advancing R&D to help bringing to market sustainable energy sources.”

The research was partially supported by the Flemish Strategisch Initiatief Materialen SoPPoM program.

The technology will be presented this week at Intersolar 2013 in San Francisco.

For more information, visit: www.imec.be, www.solliance.eu or www.uhasselt.be/IMO