Print Email Facebook Twitter Trapping and Detrapping in Colloidal Perovskite Nanoplatelets Title Trapping and Detrapping in Colloidal Perovskite Nanoplatelets: Elucidation and Prevention of Nonradiative Processes through Chemical Treatment Author Vonk, Sander J.W. (Universiteit Utrecht) Fridriksson, M.B. (Universiteit Utrecht) Hinterding, Stijn O.M. (Universiteit Utrecht) Mangnus, Mark J.J. (Universiteit Utrecht) Van Swieten, Thomas P. (Universiteit Utrecht) Grozema, F.C. (TU Delft ChemE/Opto-electronic Materials) Rabouw, Freddy T. (Debye Institute) van der Stam, W. (TU Delft ChemE/Opto-electronic Materials) Date 2020 Abstract 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 CsPbBr3 nanoplatelets, before and after chemical treatment with PbBr2 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 PbBr2. 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. Subject Quantum yieldExcitonsPhysical chemical processesElectrical conductivityRecombination To reference this document use: http://resolver.tudelft.nl/uuid:c3ca5357-47f9-4d67-951e-dd3c201472ef DOI https://doi.org/10.1021/acs.jpcc.0c02287 ISSN 1932-7447 Source The Journal of Physical Chemistry C, 124 (14), 8047-8054 Part of collection Institutional Repository Document type journal article Rights © 2020 Sander J.W. Vonk, M.B. Fridriksson, Stijn O.M. Hinterding, Mark J.J. Mangnus, Thomas P. Van Swieten, F.C. Grozema, Freddy T. Rabouw, W. van der Stam Files PDF acs.jpcc.0c02287.pdf 3 MB Close viewer /islandora/object/uuid:c3ca5357-47f9-4d67-951e-dd3c201472ef/datastream/OBJ/view