NIR Luminescence from Deep-Level Traps in CsPbBr<sub>3</sub> Microcrystals
In this study, we report the first observation of a near-infrared (NIR) emission band from all-inorganic CsPbBr<sub>3</sub> and CsPb(Br/Cl)<sub>3</sub> perovskite microcrystals. By means of temperature- and power-dependent NIR and visible luminescence spectroscopy, we demonstrate that a fraction of the excited states in these materials relax through radiative transitions involving traps located deep within the band gap, leading to broadband NIR emission. The quantum yield of this deep trap emission is quantitatively determined for the first time and amounts to approximately 0.3% at room temperature. Furthermore, by examining the picosecond-to-nanosecond dynamics of the excited states, using time-resolved luminescence spectroscopy, we observe that the population of NIR initial states occurs on a 660 ps time scale, consistent with the capture of free carriers by deep trap sites. Hence, this work deepens our fundamental understanding of previously unexplored recombination channels in metal halide perovskite microcrystals.
Authors
- Yutaka Shibata (ORCID: https://orcid.org/0000-0002-7510-503X)
- Hiroshi Fukumura (ORCID: https://orcid.org/0000-0003-2392-935X)
- Jialiang Xu (ORCID: https://orcid.org/0000-0003-2441-4809)
- Yasuyuki Araki (ORCID: https://orcid.org/0000-0002-5627-7776)
- Santi Nonell (ORCID: https://orcid.org/0000-0002-8900-5291)
- Eduard Fron (ORCID: https://orcid.org/0000-0003-2260-0798)
- Jonathan B. F. Vandenwijngaerden (ORCID: https://orcid.org/0000-0001-8187-847X)
- Johan Hofkens (ORCID: https://orcid.org/0000-0002-9101-0567)
- Roger Bresolí‐Obach (ORCID: https://orcid.org/0000-0002-7819-7750)
- Elke Debroye (ORCID: https://orcid.org/0000-0003-1087-4759)
- Mark Van der Auweraer (ORCID: https://orcid.org/0000-0002-9022-1696)
- Maarten B. J. Roeffaers (ORCID: https://orcid.org/0000-0001-6582-6514)
- Bapi Pradhan (ORCID: https://orcid.org/0000-0002-6202-7343)
- Haifeng Yuan (ORCID: https://orcid.org/0000-0001-6652-3670)
- Xianjun Zhang
- Bob Van Hout
- Dario Santantonio
Institutions
- Tohoku University (JP)
- Nankai University (CN)
- Max Planck Institute for Polymer Research (DE)
- Institut Químic de Sarrià (ES)
- Universitat Ramon Llull (ES)
- Massachusetts Institute of Technology (US)
- KU Leuven (BE)
Publication Details
- Journal
- The Journal of Physical Chemistry Letters
- Published
- 2025-03-31
- DOI
- https://doi.org/10.1021/acs.jpclett.5c00545
- Citations
- 1
- Primary Topic
- Perovskite Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.73
Funders
- National Natural Science Foundation of China
- Fonds Wetenschappelijk Onderzoek
- Institució Catalana de Recerca i Estudis Avançats
- KU Leuven
- Vlaamse regering
- HORIZON EUROPE Framework Programme
- European Research Council
- Japan Society for the Promotion of Science
- Agencia Estatal de Investigación