Flexible CZTS solar cells on flexible Corning<sup>®</sup> Willow<sup>®</sup> Glass substrates

Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ZnSnS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> (CZTS) thin film solar cells were successfully fabricated on Corning <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> Willow <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> Glass substrates coated with a Molybdenum (Mo) back contact. The CZTS thin films were deposited by using magnetron sputtering followed by annealing in sulfur vapor for 30 minutes. The best conversion efficiency achieved of the flexible CZTS solar cell was 3.08%, with an active area of 0.45cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The conversion efficiency was reduced by 20% when the cell was bent to a 50mm radius. The degradation is caused by higher series resistance, which can be due to the degradation of the TCO layer and the damage in the CZTS/Mo interface.