Eu2+: A suitable substituent for Pb2+ in CsPbX3 perovskite nanocrystals?
Abstract
Eu2+ is used to replace toxic Pb2+ in metal halide perovskite nanocrystals (NCs). The synthesis implies injection of cesium oleate into a solution of europium (uc(ii)) bromide at an experimentally determined optimum temperature of 130 °C and a reaction time of 60 s. Structural analysis indicates the formation of spherical CsEuBr3 nanoparticles with a mean size of 43 ± 7 nm. Using EuI2 instead of EuBr2 leads to the formation of 18-nm CsI nanoparticles, while EuCl2 does not show any reaction with cesium oleate forming 80-nm EuCl2 nanoparticles. The obtained CsEuBr3 NCs exhibit bright blue emission at 413 nm (FWHM 30 nm) with a room temperature photoluminescence quantum yield of 39%. The emission originates from the Laporte-allowed 4f7-4f65d1 transition of Eu2+ and shows a PL decay time of 263 ns. The long-term stability of the optical properties is observed, making inorganic lead-free CsEuBr3 NCs promising deep blue emitters for optoelectronics.
- Publication:
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Journal of Chemical Physics
- Pub Date:
- December 2019
- DOI:
- 10.1063/1.5126473
- arXiv:
- arXiv:2010.07653
- Bibcode:
- 2019JChPh.151w1101A
- Keywords:
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- Physics - Chemical Physics
- E-Print:
- The Journal of Chemical Physics (2019)