1.Surface Technology Division,Korea Institute of Materials Science (KIMS),Gyeongnam,Republic of Korea;2.School of Energy and Chemical Engineering,Ulsan National Institute of Science & Technology (UNIST),Ulsan,Republic of Korea;3.Structure Analysis Group, Gyeongbuk Science & Technology Promotion Center,Future Strategy Research Institute,Gyeongbuk,Republic of Korea;4.Division of Physics and Semiconductor Science,Dongguk University,Seoul,Republic of Korea;5.Department of Chemistry Education Graduate, Department of Chemical Materials, and Institute for Plastic Information and Energy Materials,Pusan National University,Busan,Republic of Korea
Abstract:
Despite the excellent merits of lead perovskite solar cells, their instability and toxicity still present a bottleneck for practical applications. Bismuth perovskite has emerged as a candidate for photovoltaic (PV) applications, because it not only has a low toxicity but is also stable in air. However, the power conversion efficiency (PCE) remains an unsolved problem. We performed band gap tuning experiments to improve the efficiency. The absorption of ABi3I10 structure films was extended within the visible region, and the optical band gap was decreased considerably compared to that for Cs3Bi2I9. Furthermore, we explained the correlation between the structure and the optical properties via a first-principles study. A device employing CsBi3I10 as a photoactive layer exhibits a PCE of 1.51% and an excellent ambient stability over 30 days.
