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Comment on “Interplay of Structural and Optoelectronic Properties in Formamidinium Mixed Tin‐Lead Triiodide Perovskites”
Author(s) -
Baranovskii Sergei D.,
Höhbusch Pauline,
Nenashev Alexey V.,
Dvurechenskii Anatolii V.,
Gerhard Marina,
Hertel Dirk,
Meerholz Klaus,
Koch Martin,
Gebhard Florian
Publication year - 2022
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202201309
Subject(s) - formamidinium , photoluminescence , alloy , materials science , triiodide , tin , stokes shift , laser linewidth , quantum yield , condensed matter physics , analytical chemistry (journal) , luminescence , crystallography , optoelectronics , optics , chemistry , metallurgy , physics , perovskite (structure) , fluorescence , laser , electrode , electrolyte , dye sensitized solar cell , chromatography
Studying optoelectronic properties in FAPb 1− x Sn x I 3 and in FA 0.83 Cs 0.17 Pb 1− x Sn x I 3 perovskites as a function of the lead:tin content, Parrott et al. (2018) and Savill et al. (2020) observed the broadest luminescence linewidth and the largest Stokes shift in mixed compositions with Sn <25% and with >85%. It is in contrast to the intuitive expectation of the largest effects of alloy disorder for the 50:50 composition. This comment addresses the alloy disorder caused by statistical local spatial fluctuations of the alloy composition and shows that the largest effects of alloy disorder for perfectly random fluctuations in FAPb 1− x Sn x I 3 and FA 0.83 Cs 0.17 Pb 1− x Sn x I 3 are, in fact, expected for x < 0.25 and for x > 0.85. It can be one of the reasons why Pb‐rich and Sn‐rich Sn‐Pb perovskites typically show shorter photoluminescence (PL) lifetimes, broader emission, increased Stokes shifts, reduced PL quantum yield, and higher Urbach tails, compared with their lead‐only counterparts.