at Google ScholarTitle data
Haddadi Barzoki, Fatemeh ; Griesbach, Markus ; Köhler, Anna ; Grüninger, Helen:
Finite Size Effects on Light-Induced Correlated Ionic and Electronic Transport in Mixed Halide Perovskites.
In: ACS Energy Letters.
Vol. 11
(2026)
Issue 3
.
- pp. 2829-2840.
ISSN 2380-8195
DOI: https://doi.org/10.1021/acsenergylett.5c04123
Project information
| Project title: |
Project's official title Project's id Entwicklung von Struktur, Ionenwanderung und Defekteigenschaften während der (Ent-)Mischung von Bleihalogenid-Perowskiten verstehen (DE-MIX) 506642499 SFB 1585: Strukturierte Funktionsmaterialien für multiplen Transport in nanoskaligen räumlichen Einschränkungen 492723217 |
|---|---|
| Project financing: |
Deutsche Forschungsgemeinschaft |
Abstract in another language
Mixed halide perovskites often undergo reversible phase segregation under illumination, yet the exact underlying mechanism and the material properties affecting this process remain unclear. By combining time-resolved photoluminescence (TRPL) with in situ X-ray diffraction (XRD) under illumination, we show that segregation kinetics and the thermodynamic limit of segregation under illumination in MAPbI1.5Br1.5 are not intrinsically linked. The segregation rate increases linearly with the defect density inferred from TRPL. In contrast, the equilibrium extent of segregation is independent of defect density but instead decreases with reducing crystallite size down to a critical, finite-size threshold of ∼40 nm, below which segregation is suppressed. Defect passivation using the ionic liquid BMIMBF4 slows the segregation kinetics but does not affect equilibrium limits. These findings establish crystallite size as a thermodynamic constraint and defects as kinetic mediators, outlining considerations for designing photostable mixed halide perovskites.