Enhancing the emission intensity and decreasing the full widths at half maximum of Ba₃Si₆O₁₂N₂:Eu²⁺ by Mg²⁺ doping

Abstract

The promising green oxynitride phosphor, Ba3-xMgxSi6O12N2:Eu(2+) was synthesized by the solid-state reaction method. The effect of Mg(2+) doping on the structure and photoluminescence (PL) properties of Ba3Si6O12N2:Eu(2+) was investigated systematically. The results reveal that the phosphor retains the single phase of Ba3Si6O12N2, with the lattice expanding upon increasing the Mg(2+) concentration, in an appropriate range. This suggests that a large portion of Mg(2+) enters into the interstitial sites of the crystal lattice. At a certain concentration, Mg(2+) doping can greatly enhance the absorption and PL intensity and decrease the full widths at half maximum (FWHM) of Ba3Si6O12N2:Eu(2+) phosphors. The green phosphor Ba2.87Eu0.1Mg0.03Si6O12N2 exhibited a small thermal quenching, which remained 82% of the initial emission intensity when measured at 150 °C. The quantum efficiency measured at 400 nm excitation was 38.5%. All the results indicate that the solid solution Ba3-xMgxSi6O12N2:Eu(2+) can be a good candidate for phosphors applicable in n-UV LEDs for solid-state lighting.

A broadband cyan-emitting Ca2LuZr2(AlO4)3:Ce3+ garnet phosphor for near-ultraviolet-pumped warm-white light-emitting diodes with an improved color rendering index

“…[1][2][3][4][5][6][7][8] Currently, the mainstream preparation approach of the white LEDs is to coat blue LED chips with YAG:Ce 3+ yellow-emitting phosphors, which is a simple structure and relatively mature production method. [9][10][11][12][13][14][15] However, the white light made from such a relatively mature production method suffers from a high correlated color temperature (CCT 4 4500 K) and a low color rendering index (CRI; Ra o 80) due to lack of red spectral component. 8,[16][17][18][19] Alternatively, a new approach of coating the near-ultraviolet (near-UV) LED chips (380-420 nm) with the tricolor phosphors (blue, green, and red) was proposed to fabricate white LEDs, which have been considered as the next-generation LED devices due to their high CRI values.…”

Photoluminescence tuning of Ca5(PO4)3Cl:Ce3+/Eu2+,Tb3+/Mn2+ phosphors: structure refinement, site occupancy, energy transfer and thermal stability

“…5 To improve the colorrendering index of current pc-WLEDs and realize warm white lighting, a feasible strategy is to combine near ultraviolet (n-UV) LED chips (340-420 nm) with red, green, and blue phosphors. [6][7][8][9] Unfortunately, the n-UV based WLEDs have low luminescence efficiency due to the unavoidable reabsorption of blue light by the red and green phosphors. 10 In addition, the mixing of multi-phosphors often results in color unbalance at the higher operating temperature, device complication, and high-cost problems.…”

Dual-Mode Manipulating Multicenter Photoluminescence in a Single-Phased Ba9Lu2Si6O24:Bi3+, Eu3+ Phosphor to Realize White Light/Tunable Emissions

“…It is well known that the activation energy ( E a ) is a good indicator to assess the thermal stability of phosphors 31 . It can be calculated from the Arrhenius equation 32 :where I 0 and I are the integrated intensity at room temperature and a particular operating temperatures, respectively; E a and T are the calculated activation energy and the operating temperature (K), respectively; A and k are a constant for a certain host and the Boltzmann constant (8.62 × 10 −5 eV K −1 ), respectively. As depicted in Fig.…”