Synthesis and characterization of europium (III), terbium (III) complexes and their mixture for making white light emission powder

The enhanced luminescence of lanthanide complexes coordinated to antenna ligands has potential applications for developing devices like screens and lamps. Herein, three β-diketone antenna ligands were incorporated into Eu(III) and Tb(III) metals to synthesize five complexes. Their luminescence properties in solid state and the energy levels of the electronic states for the ligands and the metals were recorded and probed by UV–vis and fluorescence spectroscopies. Under UV light, a white-light emission powder was observed by mixing red-emission europium and green-emission terbium complexes, with blue-emission laundry powder. The powder composition was tuned by using spectroscopic analysis and CIE 1931 color diagram

Amplified Photoluminescence of CsPbX3 Perovskites Confined in Silica Film with a Chiral Nematic Structure

Metal halide perovskites (MHPs, CsPbX3: X = Cl, Br, I) have advanced the field of optoelectronic devices due to their remarkable light-emitting capabilities, stemming from the large overlap between their emission and absorption spectra, offering the possibility to reabsorb their own emitted photons. Herein, a straightforward method is reported to confine CsPbBr into mesoporous silica films with a chiral nematic structure, allowing the amplification of the photoluminescence (PL). The simple room temperature ligand-free synthesis allows facile growth of CsPbBr in silica photonic films, in which the Bragg peak position can be tuned from the UV to the visible range. The perovskite/silica films demonstrate a remarkable improvement in PL intensity and lifetime compared to the as-synthesized non-confined perovskite nanocrystals (NCs) due to the overlap of the Bragg peak position of the chiral nematic photonic films and CsPbBr absorption band. Such a PL enhancement stems from the slow photon effect induced at blue and red Bragg peak edges that facilitates the photon recycling of the emitted photons. This innovative approach offers a new way to fabricate highly emissive and long-lived photoluminescent films at ambient conditions, potentially advancing perovskite utilization in light-emitting devices