WO2005034247-A1  TERHEGGEN ET AL.: 'Ga2O3 segregation in Cu(In,Ga)Se2/ZnO superstrate solar cells and its impact on their photovoltaic properties' THIN SOLID FILMS vol. 403-404, 2002, pages 212 - 215, XP004430356;  DELAHOY ET AL: 'Charging and discharging of defect states in CIGS/ZnO junctions' THIN SOLID FILMS vol. 361-362, 2000, pages 140 - 144, XP004187459;  NISHIWAKI ET AL.: 'Preparation of Zn doped Cu(In,Ga)Se2 thin films by physical vapor deposition for solar cells' SOLAR ENERGY MATERIALS & SOLAR CELLS vol. 77, no. 4, 01 June 2003, pages 359 - 368, XP004418487;  RAMANATHAN ET AL.: 'Surface treatment of CuInGaSe2 thin films and its effect on the photovoltaic properties of solar cells' NATIONAL RENEWABLE ENERGY LABORATORY CONFERENCE PAPER PREPRINT October 2002, COLORADO, USA, pages 1 - 6, XP002986128;  YAMADA ET AL.: 'Buried pn homojunction in Cu(InGa)Se2 solar cells formed by intentional Zn doping' CONFERENCE RECORD OF THE 28TH PHOTOVOLTAIC SPECIALISTS CONFERENCE, IEEE 15 September 2000 - 22 September 2000, pages 462 - 465, XP002986129;  NISHIWAKI ET AL.: 'Preparation of Zn doped Cu(In,Ga)Se2 thin films by physical vapor deposition for solar cells' SOLAR ENERGY MATERIALS&SOLAR CELLS vol. 77, no. 4, 01 June 2003, pages 359 - 368, XP004418487US7179677-B2  "Chemical Vapor Deposited Copper Indium Diselenide Thin Film Materials Research" Final Report, Mar. 1984, SERI/STR-211-2247.;  Delahoy et al. Charging and Discharging of Defect States in CIGS/ZnO Junctions. Thin Solid Films. 2000, vol. 361-362, pp. 140-144, especially p. 361.;  Nishiwaki et al. Preparation of Zn Doped Cu(InGa)Se2 Thin Films by Physical Vapor Deposition for Solar Cells. Solar Energy Materials & Solar Cells. Jun. 1, 2003, vol. 77, No. 4, pp. 359-368, especially pp. 360-361.;  Ramanathan et al., "Surface Treatment of CuInGaSe2 Thin Films and Its Effect on the Photovoltaic Properties of Solar Cells" In: National Renewable Energy Laboratory conference paper preprint. NREL: Colorado, Oct. 2002, pp. 1-6, especially p. 1.;  Terheggen et al., Ga203 segregation in Cu(In, Ga)Se2/ZnO superstrate solar cells and its impact on their photovoltaic properties.;  Tomar, M.S. and Garcia, F.J., "A ZnO/p-CuInSe2 Thin Film Solar Cell Prepared Entirely by Spray Pyrolysis," Thin Solid Films, 90 (1982), pp. 419-423.;  Yamada et al. Buried pn Homojunction in Cu(InGa)Se2 solar cells formed by intentional Zn doping. In: Conference Record of the 28th Photovoltaic Specialists Conference. IEEE, Sep. 15-22, 2000, pp. 462-465, epecially p. 462.