With the aim of achieving 20% conversion efficiencies but with lower material costs, Solliance and imec have demonstrated a CZTSe (Cu2ZnSnSe4)-based thin-film solar cell (1x1cm2, AM1.5G) with 9.7% efficiency.
Imec’s associated lab at the Hasselt University, imomec fabricated the CZTSe layers by sputtering Cu, Zn and Sn metal layers on a Molybdenum-on-glass substrate with a subsequent anneal in an H2Se containing atmosphere.
The highest efficiency said to have been obtained was 9.7%, with a maximum short circuit current of 38.9mA/cm2, an open circuit voltage of 0.41V and a fill factor of 61 percent.
The 1x1cm2 cell was produced with polycrystalline absorber layers only 1µm thick, with a typical grain size of about 1µm, according to the researchers.
“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 Solliance of the alternative thin-film PV program. “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 material availability of CZTSe compared to CIGS is seen as a key benefit, which would be expected to enable lower material costs despite high-volume manufacturing in the future.
More details are being provide by Solliance and imec at next week’s Intersolar NA conference in San Francisco.
