Research teams at the HZB and at the University of Limerick,
Ireland, have discovered a novel solid state reaction which lets kesterite
grains grow within a few seconds and at relatively low temperatures. For this
reaction they exploit a transition from a metastable wurtzite compound in the
form of nanorods to the more stable kesterite compound. At the EDDI Beamline at
BESSY II, the scientists could observe this process in real-time when heating
the sample: in a few seconds Kesterite grains formed. The size of the grains
was found to depend on the heating rate. With fast heating they succeeded in
producing a Kesterite thin film with near micrometer-sized crystal grains,
which could be used in thin film solar cells. These findings have now been
published in the journal “Nature Communications”.