The present paper aims at stating when and why small grains transform to large grains during Cu(In,Ga)Se2 film growth following three-step processes. Experimental observations revealed that such recrystallization was achieved when the nominal composition of the films was close to a 1:1:2 stoichiometry. A new model based on grain boundary migration theory was proposed in order to establish a causal relationship between such a composition threshold and grain boundary motion yielding large grain formation. This model was related to some of the experimental observations related to Cu(In,Ga)Se2 layer growth that had previously been difficult to explain.

Recrystallization of CIGSe Layers Grown by Three-Step Processes: a Model Based on Grain Boundary Migration. N.Barreau, T.Painchaud, F.Couzinié-Devy, L.Arzel, J.Kessler: Acta Materialia, 2010, 58[17], 5572-7