Ivan Scheblykin
Professor
Self-Healing Ability of Perovskites Observed via Photoluminescence Response on Nanoscale Local Forces and Mechanical Damage
Author
Summary, in English
The photoluminescence (PL) of metal halide perovskites can recover after light or current-induced degradation. This self-healing ability is tested by acting mechanically on MAPbI3 polycrystalline microcrystals by an atomic force microscope tip (applying force, scratching, and cutting) while monitoring the PL. Although strain and crystal damage induce strong PL quenching, the initial balance between radiative and nonradiative processes in the microcrystals is restored within a few minutes. The stepwise quenching–recovery cycles induced by the mechanical action is interpreted as a modulation of the PL blinking behavior. This study proposes that the dynamic equilibrium between active and inactive states of the metastable nonradiative recombination centers causing blinking is perturbed by strain. Reversible stochastic transformation of several nonradiative centers per microcrystal under application/release of the local stress can lead to the observed PL quenching and recovery. Fitting the experimental PL trajectories by a phenomenological model based on viscoelasticity provides a characteristic time of strain relaxation in MAPbI3 on the order of 10–100 s. The key role of metastable defect states in nonradiative losses and in the self-healing properties of perovskites is suggested.
Department/s
- LTH Profile Area: Nanoscience and Semiconductor Technology
- Chemical Physics
- LU Profile Area: Light and Materials
- LTH Profile Area: Photon Science and Technology
- NanoLund: Centre for Nanoscience
Publishing year
2023
Language
English
Publication/Series
Advanced Science
Volume
10
Issue
1
Document type
Journal article
Publisher
John Wiley & Sons Inc.
Topic
- Condensed Matter Physics (including Material Physics, Nano Physics)
Keywords
- defects
- metastability
- photoluminescence
- self-healing
- strain
Status
Published
ISBN/ISSN/Other
- ISSN: 2198-3844