Ce⁴⁺-Based Compounds Capable of Photoluminescence by Charge Transfer Excitation under Near-Ultraviolet–Visible Light

Abstract

Ce 4+ -based charge transfer phosphor is not common and has been reported mainly in Sr 2 CeO 4 with an excitation band peaking at ∼290 nm, mismatching with the near-ultraviolet light emitting diodes. Herein, we report a new series of Ce 4+based compounds Sr 4.4 Ce 2.6 REZnO 12 (RE = Y, La, and Eu) capable of photoluminescence induced by O 2− −Ce 4+ charge transfer excitation under near-ultraviolet−visible light. The crystal structure of Sr 4.4 Ce 2.6 EuZnO 12 was determined by single crystal X-ray diffraction. The RE = La and Y samples were confirmed to be iso-structure compounds of the RE = Eu sample by powder X-ray diffraction. By introducing highly covalent Zn 2+ −O 2− bonds into the framework, the Ce 4+ −O 2− bonds are lengthened due to the effect of the Ce 4+ −O 2− −Zn 2+ stretch. The lengthened Ce 4+ −O 2− bond weakens the repulsion of the electrons between Ce 4+ and O 2− , thereby lowering the charge transfer energy to the visible light region. Incorporation of Eu 3+ into the present compounds realized red emission under near-ultraviolet−visible excitation by the O 2− −Ce 4+ charge transfer followed by energy transfer to Eu 3+ .

Temporally and spatially resolved molecular profiling in fingerprint analysis using indium vanadate nanosheets-assisted laser desorption ionization mass spectrometry

“…Figure 2 g demonstrated decreasing deprotonated ion peaks of of LA (m/z 199.2) and OA (m/z 281.2) with an increase in KSCN concentration (0, 5, 10, 20 µmol/mL), showing a distinct suppression of the MS signal of the two fatty acids in the presence of higher KSCN concentration, thus experimentally supporting the electronic transition mechanism in Fig. 2 g [ 39 ]. Consequently, the electronic structure and optoelectronic properties of IVONSs:Sm should be examined.…”