Media type: E-Article Title: Cu(InGa)Se2 solar cells on a flexible polymer web Contributor: Birkmire, Robert; Eser, Erten; Fields, Shannon; Shafarman, William imprint: Wiley, 2005 Published in: Progress in Photovoltaics: Research and Applications Language: English DOI: 10.1002/pip.605 ISSN: 1062-7995; 1099-159X Keywords: Electrical and Electronic Engineering ; Condensed Matter Physics ; Renewable Energy, Sustainability and the Environment ; Electronic, Optical and Magnetic Materials Origination: Footnote: Description: <jats:title>Abstract</jats:title><jats:p>Deposition of CuInGaSe<jats:sub>2</jats:sub> films on 6‐inch wide Mo coated polyimide web substrate in a roll‐to‐roll vapor deposition system from elemental sources is described. Material transport from the sources to the moving web substrate has been modeled by combining an evaporative effusion model and the gas flow kinetics and by experimentally determining the flux intensity profile. The model gives a reasonably good approximation of the Ga profile in the films. Poor adhesion of the selenide film to molybdenum has been resolved by depositing a thin layer of β‐(Ga<jats:sub>0.8</jats:sub>In<jats:sub>0.2</jats:sub>)<jats:sub>2</jats:sub>Se<jats:sub>3</jats:sub> precursor layer. Two‐dimensional compositional mapping by energy dispersive spectroscopy of 5‐feet‐long web gave 0.88 ± 1.9% and 0.28 ± 2.5% respectively for Cu/(Ga+In) and Ga/(Ga+In) ratios, indicating highly uniform film composition. This compositional uniformity translated to the uniformity in the devices fabricated on the web. The open‐circuit voltages of the devices from the centerline of the 5‐feet web were measured to be 0.529 ± 0.86%. A two‐dimensional device efficiency survey gave 9.2 ± 1%. The process was able to produce high‐quality material, as defined by the best device efficiency, for a wide range of Cu/(Ga+In) ratios. The best efficiency achieved so far was 12.1% with MgF<jats:sub>2</jats:sub> anti‐reflection coating. Copyright © 2005 John Wiley & Sons, Ltd.</jats:p>