Ivan Scheblykin
Professor
Photoluminescence Mapping over Laser Pulse Fluence and Repetition Rate as a Fingerprint of Charge and Defect Dynamics in Perovskites
Author
Summary, in English
Defects in metal halide perovskites (MHP) are photosensitive, making the observer effect unavoidable when laser spectroscopy methods are applied. Photoluminescence (PL) bleaching and enhancement under light soaking and recovery in dark are examples of the transient phenomena that are consequent to the creation and healing of defects. Depending on the initial sample composition, environment, and other factors, the defect nature and evolution can strongly vary, making spectroscopic data analysis prone to misinterpretations. Herein, the use of an automatically acquired dependence of PL quantum yield (PLQY) on the laser pulse repetition rate and pulse fluence as a unique fingerprint of both charge carrier dynamics and defect evolution is demonstrated. A simple visual comparison of such fingerprints allows for assessment of similarities and differences between MHP samples. The study illustrates this by examining methylammonium lead triiodide (MAPbI3) films with altered stoichiometry that just after preparation showed very pronounced defect dynamics at time scale from milliseconds to seconds, clearly distorting the PLQY fingerprint. Upon weeks of storage, the sample fingerprints evolve toward the standard stoichiometric MAPbI3 in terms of both charge carrier dynamics and defect stability. Automatic PLQY mapping can be used as a universal method for assessment of perovskite sample quality.
Department/s
- Chemical Physics
- NanoLund: Centre for Nanoscience
- LTH Profile Area: Nanoscience and Semiconductor Technology
- LTH Profile Area: Photon Science and Technology
- LU Profile Area: Light and Materials
Publishing year
2024
Language
English
Publication/Series
Advanced Optical Materials
Volume
12
Issue
8
Document type
Journal article
Publisher
John Wiley & Sons Inc.
Topic
- Atom and Molecular Physics and Optics
Keywords
- defects
- photoluminescence
- photosensitivity
- PLQY
- semiconductors
Status
Published
ISBN/ISSN/Other
- ISSN: 2195-1071