ChemInform Abstract: Promising Oxonitridosilicate Phosphor Host Sr₃Si₂O₄N₂: Synthesis, Structure, and Luminescence Properties Activated by Eu²⁺ and Ce³⁺/Li⁺ for pc‐LEDs.

Abstract

The title compound is prepared by solid state reaction of SrCO3, α‐Si3N4, and SiO2 (W crucibles, 1550 °C, 8 h).

Strong Room Temperature Blue Emission from Rapid Thermal Annealed Cerium-Doped Aluminum (Oxy)Nitride Thin Films

“…These samples have then been annealed in Ar atmosphere. Fig (7) shows the PL of these samples excited by 325 nm. The PL intensity of the N-rich sample is stronger than that of Al-rich sample, which is consistent with the excitation mechanisms proposed.…”

“…In this line, Ce 3+ and Eu 2+ are the most frequently used activators due to their luminescence properties attributed to fully allowed electric dipole 5d-4f transitions that lead to a large absorption cross section in UV-visible range. [4][5][6][7][8] However, Ce 3+ is particularly interesting due to its fast and efficient luminescence in UV-blue regions. [9][10] Ce 3+ has only one electron in its 4f state.…”

Color-Tunable and Highly Luminous N3–-Doped Ba2–xCaxSiO4−δN2/3δ:Eu2+ (0.0 ≤ x ≤ 1.0) Phosphors for White NUV-LED

“…(Ca = 0.5, 0.8, 1.0) phosphors, it is interesting that the emission peak maxima gradually changes to the red-shifted region with increasing Ca content; 443 nm for Ca = 0.5, 478 nm for Ca = 0.8, 485 nm for Ca = 1.0. The correlation between the crystal field splitting and the shape and size of the polyhedron is given in the following equation 45,46 = D Ze r R 3 /5 q 2 4 5 (4) where D q represents crystal field strength, Z represents the valence of the anion ligand, e represents the charge, r represents radius of frontier d wave function, and R represents the bond length between a center ion and ligands. According to eq 4, the crystal field strength of BCSON:Eu 0.02 2+ phosphor with the higher Ca content increases because the ionic radius of Ca 2+ (1.18 Å at CN = 9) is smaller than that of Ba 2+ (1.47 Å at CN = 9).…”

“…The general requirements for LED phosphors are as follows: 2,3 (i) excitation spectra overlapping with emission spectra of blue LED or near UV LED, (ii) emission spectra lying in the green and red region for blue LED or RGB region for near UV LED, (iii) high quantum efficiency, (iv) optimal grain size of phosphors, (v) high thermal stability of luminescence, (vi) high chemical stability, (vii) low production cost, (viii) environmentally friendly composition. The silicate-based phosphor materials have been extensively studied as expressed in the following formulas: Sr 3 Si 2 O 4 N 2 :Eu 2+ , 4 Ba 1.55 Ca 0.45 SiO 4 :Eu 2+ /Mn 2+ , 5 MSi 2 O 2−δ N 2+2/3δ :Eu 2+ /Ce 3+ (M = Ca, Sr, Ba), 6 CaAlSi-N 3 :Eu 2+ , 7 Na x Ca 1−x Al 2−x Si 2+x O 8 :Eu 2+ . 8 It is well known that Ce 3+ and Eu 2+ activators have been widely used to develop the luminescent properties of the color conversion LED phosphors because of the advantages of their PL properties, i.e., excitation and emission bands formation due to d → f transitions with the more intense emission than those originating from f → f transitions.…”

A Garnet-Based Ca2YZr2Al3O12:Eu3+ Red-Emitting Phosphor for n-UV Light Emitting Diodes and Field Emission Displays: Electronic Structure and Luminescence Properties

“…It is generally accepted that the DFT calculation may underestimate the band gap in some ways, so the experimental value of the band gap corresponds with the calculated value. 18,21,22 Figure 5 exhibits the PL and PLE spectra of the representative CYZA:0.08Eu 3+ sample. The PLE spectrum was obtained by monitoring the emission peak at 611 nm, which consists of a broad band with the maximum at 256 nm and several sharp peaks ranging from 300 to 500 nm.…”