Trapping and Detrapping in Colloidal Perovskite Nanoplatelets: Elucidation and Prevention of Nonradiative Processes through Chemical Treatment.

Autor: Vonk SJW; Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands., Fridriksson MB; Opto-Electronic Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands., Hinterding SOM; Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands., Mangnus MJJ; Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands., van Swieten TP; Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands., Grozema FC; Opto-Electronic Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands., Rabouw FT; Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands., van der Stam W; Opto-Electronic Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands.
Jazyk: angličtina
Zdroj: The journal of physical chemistry. C, Nanomaterials and interfaces [J Phys Chem C Nanomater Interfaces] 2020 Apr 09; Vol. 124 (14), pp. 8047-8054. Date of Electronic Publication: 2020 Mar 18.
DOI: 10.1021/acs.jpcc.0c02287
Abstrakt: Metal-halide perovskite nanocrystals show promise as the future active material in photovoltaics, lighting, and other optoelectronic applications. The appeal of these materials is largely due to the robustness of the optoelectronic properties to structural defects. The photoluminescence quantum yield (PLQY) of most types of perovskite nanocrystals is nevertheless below unity, evidencing the existence of nonradiative charge-carrier decay channels. In this work, we experimentally elucidate the nonradiative pathways in CsPbBr 3 nanoplatelets, before and after chemical treatment with PbBr 2 that improves the PLQY. A combination of picosecond streak camera and nanosecond time-correlated single-photon counting measurements is used to probe the excited-state dynamics over 6 orders of magnitude in time. We find that up to 40% of the nanoplatelets from a synthesis batch are entirely nonfluorescent and cannot be turned fluorescent through chemical treatment. The other nanoplatelets show fluorescence, but charge-carrier trapping leads to losses that are prevented by chemical treatment. Interestingly, even without chemical treatment, some losses due to trapping are mitigated because trapped carriers spontaneously detrap on nanosecond-to-microsecond timescales. Our analysis shows that multiple nonradiative pathways are active in perovskite nanoplatelets, which are affected differently by chemical treatment with PbBr 2 . More generally, our work highlights that in-depth studies using a combination of techniques are necessary to understand nonradiative pathways in fluorescent nanocrystals. Such understanding is essential to optimize synthesis and treatment procedures.
Competing Interests: The authors declare no competing financial interest.
(Copyright © 2020 American Chemical Society.)
Databáze: MEDLINE
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