2020/10/02 by Gwisu Kim, Hanul Min, Kyoung Su Lee +3 · 8 citations
Engineering · Materials Science · #Chalcogenide Semiconductor Thin Films #Perovskite Materials and Applications #Solid-state spectroscopy and crystallography
paper · doi:10.1126/science.abc4417
openalex publication_date 2020/10/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Relieving unwanted strain Although the α-phase of formamidinium lead iodide (FAPbI 3 ) has a suitable bandgap for use in solar cells, it must be stabilized with additional cations. These compositions can adversely affect the bandgap and produce lattice strain that creates trap sites for charge carriers. Kim et al. found that substituting small, equimolar amounts of cesium and methylenediammonium cations for formamidinium reduced the lattice strain and trap densities. The enhancement in open-circuit voltage led to a certified power conversion efficiency of 24.4%, and encapsulated devices retained 90% of their initial efficiency after 400 hours of maximal power point operating conditions. Science , this issue p. 108