Microscopic insight into the reversibility of photodegradation in MAPbI₃ thin films

Summary, in English

Whether optoelectronic devices based on metal-halide perovskite semiconductors will become a commercially viable technology will be determined by their intrinsic and operational stability. Recent results indicate there is some reversibility of perovskite degradation in thin films and devices, although mechanistic insight into the processes driving degradation and recovery are still scarce. We here present a comparative spectroscopic study of methylammonium lead iodide (MAPbI₃) films having undergone either photo- or thermal degradation under controlled conditions. We confirm that the degradation mechanism pertaining to each type of stress is inherently different. Our results from photoluminescence microscopy measurements paint a spatially, spectrally and temporarily resolved picture showing that, unlike thermally degraded samples, photodegraded samples are in a state that intermittently recovers to luminescent MAPbI₃ upon laser excitation. This indicates that rather than irreversibly decomposing, photoinduced degradation leaves MAPbI₃ structurally or compositionally intact but induces defects causing non-radiative recombination losses.

• Author: Aboma Merdasa; Sergey Tsarev; Azat F. Akbulatov; Pavel Troshin; Eva L. Unger
• Department/s: Chemical Physics; NanoLund: Centre for Nanoscience
• Publishing year: 2020
• Language: English
• Publication/Series: Journal of Luminescence
• Volume: 219
• Links: http://dx.doi.org/10.1016/j.jlumin.2019.116916
• Document type: Journal article
• Publisher: Elsevier
• Topic: Physical Chemistry
• Status: Published
• ISBN/ISSN/Other: ISSN: 0022-2313