Aboma Merdasa
Researcher
Impact of Excess Lead Iodide on the Recombination Kinetics in Metal Halide Perovskites
Author
Summary, in English
Fundmental comprehension of light-induced processes in perovskites are still scarce. One active debate surrounds the influence of excess lead iodide (PbI2) on device performance, as well as optoelectronic properties, where both beneficial and detrimental traits have been reported. Here, we study its impact on charge carrier recombination kinetics by simultaneously acquiring the photoluminescence quantum yield and time-resolved photoluminescence as a function of excitation wavelength (450-780 nm). The presence of PbI2 in the perovskite film is identified via a unique spectroscopic signature in the PLQY spectrum. Probing the recombination in the presence and absence of this signature, we detect a radiative bimolecular recombination mechanism induced by PbI2. Spatially resolving the photoluminescence, we determine that this radiative process occurs in a small volume at the PbI2/perovskite interface, which is only active when charge carriers are generated in PbI2, and therefore provide deeper insight into how excess PbI2 may improve the properties of perovskite-based devices.
Department/s
- Chemical Physics
- NanoLund: Centre for Nanoscience
Publishing year
2019
Language
English
Pages
1370-1378
Publication/Series
ACS Energy Letters
Document type
Journal article
Publisher
The American Chemical Society (ACS)
Topic
- Condensed Matter Physics
- Materials Chemistry
Status
Published
ISBN/ISSN/Other
- ISSN: 2380-8195