Optoelectronic characterization of co-evaporated and low-cost Cu(In,Ga)Se2 solar cells, a comparison

► Highly efficient and low-cost Cu(In,Ga)Se2 solar cells are investigated. ► Recombination mechanisms are determined. ► Current collection is studied by bias-dependent spectral photocurrent measurement. ► Activation energy is low for interface-dominated recombination.