TY - JOUR

T1 - Comment on “Interplay of Structural and Optoelectronic Properties in Formamidinium Mixed Tin-Lead Triiodide Perovskites”

AU - Baranovskii, Sergei D.

AU - Höhbusch, Pauline

AU - Nenashev, Alexey V.

AU - Dvurechenskii, Anatolii V.

AU - Gerhard, Marina

AU - Hertel, Dirk

AU - Meerholz, Klaus

AU - Koch, Martin

AU - Gebhard, Florian

N1 - Funding Information: S.D.B., D.H., and K.M. acknowledge financial support by the Deutsche Forschungsgemeinschaft (Research Training Group “TIDE”, RTG2591) as well as by the key profile area “Quantum Matter and Materials (QM2)” at the University of Cologne. K.M. further acknowledges support by the DFG through the project ASTRAL (ME1246‐42). Publisher Copyright: © 2022 The Authors. Advanced Functional Materials published by Wiley-VCH GmbH.

PY - 2022/7/25

Y1 - 2022/7/25

N2 - Studying optoelectronic properties in FAPb1−xSnxI3 and in FA0.83Cs0.17Pb1−xSnxI3 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 FAPb1−xSnxI3 and FA0.83Cs0.17Pb1−xSnxI3 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.

AB - Studying optoelectronic properties in FAPb1−xSnxI3 and in FA0.83Cs0.17Pb1−xSnxI3 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 FAPb1−xSnxI3 and FA0.83Cs0.17Pb1−xSnxI3 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.

KW - alloy perovskites

KW - bandgap bowing

KW - disorder effects

UR - http://www.scopus.com/inward/record.url?scp=85130477577&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/14a887a5-8cbb-3dd7-8f5b-d1685b72b22c/

U2 - 10.1002/adfm.202201309

DO - 10.1002/adfm.202201309

M3 - Article

AN - SCOPUS:85130477577

VL - 32

JO - Advanced Functional Materials

JF - Advanced Functional Materials

SN - 1616-301X

IS - 30

M1 - 2201309

ER -