Advanced characterization and in-situ growth monitoring of Cu(In,Ga)Se2 thin films and solar cells

•Overview of advanced characterization work at Helmholtz-Zentrum Berlin.•In-situ monitoring of Cu(In,Ga)Se2 growth via X-ray diffraction and light scattering.•Structural characterization and analyses of surfaces and interfaces.•Microscopic studies of structure–property relationships of Cu(In,Ga)Se2 thin films.•Optical analysis via luminescence spectroscopy.