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.
Предметные области OECD FOS+WOS
- 2.05 ТЕХНОЛОГИЯ МАТЕРИАЛОВ
- 1.03 ФИЗИЧЕСКИЕ НАУКИ И АСТРОНОМИЯ
- 1.04 ХИМИЧЕСКИЕ НАУКИ