The effect of NaF on Cu(In, Ga)Se2 thin film solar cells

This work investigates NaF, on Mo coated sodium barrier glass, as a sodium precursor for the growth of Cu(In, Ga)Se2 for thin film solar cells. These precursor layers are investigated by X-ray photoelectron spectroscopy (XPS) before and after annealing, and after exposure to selenium. XPS is also performed on the Cu(In, Ga)Se2 layer, deposited with NaF. The influence of the NaF on the absorber growth is studied by Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). The electrical properties are investigated by cell fabrication and characterization. Cell results are comparable when NaF or out-diffusion of sodium from the soda lime glass are used.