4:00 PM - 4:50 PM [17p-P10-11] Improvement of FA0.9Cs0.1Pb(I0.65Br0.35)3 thin film for the fabrication of tandem solar cells 〇Kazushi Shimomura1, Ryo Ishikawa1, Keiji Ueno1, Shirai Hajime1 (1.Saitama Univ.)