Synthesis and optical properties of perovskite nanocrystals in glass with cationic substitution

• Published in: The Journal of chemical physics 2024-09, Vol.161 (12)
• Main Authors: Kuznetsova, Maria S., Kolobkova, Elena V., Bataev, Matvey N., Berdnikov, Vladimir S., Pankin, Dmitrii V., Smirnov, Mikhail B., Ubyivovk, Evgenii V., Ignatiev, Ivan V.
• Format: Article
• Language: English
• Subjects: Cadmium; Chemical synthesis; Cryoforming; Cryogenic temperature; Diffraction patterns; Hexagonal phase; Lattice parameters; Nanocrystals; Optical properties; Perovskites; Photoluminescence
• ISSN: 0021-9606; 1089-7690; 1089-7690
• DOI: 10.1063/5.0227459

The effect of cadmium ions introduced into fluorophosphate glass on the growth and photoluminescence (PL) of the CsPb1–xCdxBr3 perovskite nanocrystals (NCs) is systematically studied. The x-ray diffraction patterns have shown that cadmium ions are really incorporated into the NCs that results in a decrease in the lattice constant from 5.85 (x = 0) to 5.75 Å (x = 0.45). At the large cadmium content in the glass (x > 0.38), simultaneous formation of the perovskite CsPb1–xCdxBr3 NCs and the non-luminescent CsCdBr3 NCs in the hexagonal phase is found. It is also found that the lattice contraction leads to an increase in the bandgap energy and a noticeable shift of the PL band to the blue region of the spectrum (from 2.42 to 2.68 eV) with a drop in quantum yield from 85% for CsPbBr3 NCs down to 4% for CsPb0.55Cd0.45Br3 NCs. It is shown that the PL quantum yield decreases due to the formation of deep trap states, which manifest themselves as a PL band in the energy range of 1.6–2.5 eV at cryogenic temperatures. A simple model explaining the behavior of the PL band as a function of temperature in the range from 30 to 300 K is proposed.