A study of fluorine doping azo transparent conductive oxide films for thin film copper indium gallium selenide solar cells on flexible substrates

Transparent conductive oxide film properties impact both performance and reliability of solar products. High optical transmission and good moisture stability is desired. In this paper we present results for Fluorine doped AZO study. Two deposition techniques (DC sputtering from zinc fluoride doped AZO target and reactive sputtering in CF4 gas) were used to baseline and study full compositional space. The optical properties, sheet resistance, composition, IV characteristics and moisture stability of the resulting films are compared to non-fluorine doped AZO films. Addition of Fluorine to AZO improved optical transmission and moisture stability without impacting electrical performance resulting in improved conversion efficiencies of completed thin film CIGS solar cells.