Solar cells with Cu(In,Ga)Se 2 absorber layers prepared by three-stage co-evaporation with varying selenium-to-metal flux ratio were studied in terms of their metastable properties. In particular, transient behaviour of the open-circuit voltage V oc after relaxation to the stable state was investigated. A linear dependence of V oc on a logarithmic time scale was observed, the slope of which is taken as a measure for the degree of metastability. Surprisingly, upon variation of selenium flux, the slope parameter systematically varies between negative and positive values, and there are process parameters, for which the V oc transient disappears. We discuss these findings within the framework of the well-known Lany–Zunger model.