Schmitz, F;
Guo, K;
Horn, J;
Sorrentino, R;
Conforto, G;
Lamberti, F;
Brescia, R;
... Gatti, T; + view all
(2020)
Lanthanide Induced Photoluminescence in Lead-Free Cs₂AgBiBr₆ Bulk Perovskite: Insights From Optical and Theoretical Investigations.
Journal of Physical Chemistry Letters
, 11
(20)
pp. 8893-8900.
10.1021/acs.jpclett.0c02317.
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Abstract
The search for materials substituting toxic lead in metal halide perovskites has recently placed emphasis on the Cs2AgBiBr6 double perovskite as a possible candidate. The poor light-emissive features of this species, mainly associated to the indirect nature of the band gap and the strongly bound exciton, however, currently make it unsuitable for solid-state lighting applications. Doping with lanthanides is an established strategy to implement luminescence in poorly emissive materials, with the additional advantage of tuning the wavelength of emission independently from the host band structure. We discuss here the impact of Eu- and Yb-doping on the absorption and emission properties of Cs2AgBiBr6 polycrystalline thin films, obtained from solution-processing of hydrothermally synthesized bulk crystalline powders, by combining experiments and density functional theory calculations. Eu(III) incorporation does not lead to the characteristic 5D0→7F2 emission feature at 2 eV, while only a weak sub band-gap radiative emission ascribed to a trap-assisted recombination process is reported. On the other hand, we demonstrate that Yb(III) incorporated in the bulk double perovskite leads to an intense and exclusive photoluminescence emission in the near-infrared (NIR) from thin films, as a result of the efficient sensitization of the lanthanide centered 2F5/2→2F7/2 transition, with favorable mid-gap energetic position. Yb-doping may be thus exploited for the future development of stable and sustainable perovskite NIR-light emitters.
| Type: | Article |
|---|---|
| Title: | Lanthanide Induced Photoluminescence in Lead-Free Cs₂AgBiBr₆ Bulk Perovskite: Insights From Optical and Theoretical Investigations |
| Location: | United States |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1021/acs.jpclett.0c02317 |
| Publisher version: | http://dx.doi.org/10.1021/acs.jpclett.0c02317 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Impurities, Thin films, Electrical conductivity Perovskites, Doping |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10111462 |
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