title: TiO2-ZnS Cascade Electron Transport Layer for Efficient Formamidinium Tin Iodide Perovskite Solar Cells.
abstract: Achieving high open-circuit voltage (Voc) for tin-based perovskite solar cells is challenging. Here, we demonstrate that a ZnS interfacial layer can improve the Vocand photovoltaic performance of formamidinium tin iodide (FASnI3) perovskite solar cells. The TiO2-ZnS electron transporting layer (ETL) with cascade conduction band structure can effectively reduce the interfacial charge recombination and facilitate electron transfer. Our best-performing FASnI3perovskite solar cell using the cascaded TiO2-ZnS ETL has achieved a power conversion efficiency of 5.27%, with a higher Vocof 0.380 V, a short-circuit current density of 23.09 mA cm-2, and a fill factor of 60.01%. The cascade structure is further validated with a TiO2-CdS ETL. Our results suggest a new approach for further improving the performance of tin-based perovskite solar cells with a higher Voc.
authors: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors: Weijun
authors: W
authors: Ke
authors: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors: Constantinos C
authors: CC
authors: Stoumpos
authors: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors: Jenna Leigh
authors: JL
authors: Logsdon
authors: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors: Michael R
authors: MR
authors: Wasielewski
authors: Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, The University of Toledo , Toledo, Ohio 43606, United States.
authors: Yanfa
authors: Y
authors: Yan
authors: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education of China, School of Physics and Technology, Wuhan University , Wuhan 430072, China.
authors: Guojia
authors: G
authors: Fang
authors: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors: Mercouri G
authors: MG
authors: Kanatzidis