Single-composition white-emitting NaSrBO₃:Ce³⁺,Sm³⁺,Tb³⁺phosphors for NUV light-emitting diodes

Abstract

Single-composition (or single-phase) phosphors have been proposed as a new strategy to overcome the concerns of emission reabsorption and different degradation rates of the three primary phosphors for light-emitting diodes (LEDs) application. A series of Ce 3+ , Sm 3+ and Tb 3+ co-doped NaSrBO 3 phosphors were synthesized via a high temperature solid-state reaction. Upon near ultraviolet (NUV) excitation, 10 tunable emissions from violet to white in visible region were realized in NaSrBO 3 :Ce 3+ , Sm 3+ , Tb 3+ phosphors by controlling the dopant concentrations. Particularly, highly efficient white-light emission with a quantum yield as high as 48.2% was achieved. The energy transfer mechanism between Ce 3+ and Sm 3+ ions in NaSrBO 3 was found to be predominantly of dipole-dipole nature. Moreover, thermal quenching effect on the photoluminescence of NaSrBO 3 :Ce 3+ , Sm 3+ , Tb 3+ was comprehensively surveyed 15 over the range of 300-600 K, showing a good thermal stability for LEDs application. By integrating this single-composition white-emitting NaSrBO 3 :Ce 3+ , Sm 3+ , Tb 3+ phosphor with a 360-nm NUV chip, we fabricated a high-performance white LED (WLED), which exhibited an excellent color rendering index Ra of 80.1 and a correlated color temperature of 6731 K with CIE coordinates of (0.311, 0.314). These findings demonstrate that the proposed single-composition white-emitting NaSrBO 3 :Ce 3+ , Sm 3+ , Tb 3+ 20 phosphors can serve as a promising phosphor for NUV-excited WLEDs.

Synthesis, structure, and luminescent properties of a family of lanthanide-functionalized peroxoniobiophosphates

“…Interestingly, the excitation spectrum of 3 upon the excitation at 546 nm consists of three dominant emission bands at 343, 353 and 378 nm, which can be ascribed to the 7 F 6 → 5 L 6 , 7 F 6 → 5 L 9 and 7 F 6 → 5 G 6 transitions (Fig. 6e), respectively 55 . The luminescence lifetime of 3 was monitored and can also conform to a single exponential function with a lifetime 18.67 μs (Figs 6f and S5).…”

Sr2Gd8(SiO4)6O2:Ce3+/Mn2+: A Single‐Component White‐Light‐Emitting Phosphor for UV W‐LEDs

“…The reason may be that the energy transfer process from Ce 3+ to Mn 2+ ions is also affected by the temperature . The activation energy for thermal quenching can be derived from the Arrhenius equation:,…”

Photoluminescence, cathodoluminescence and thermal stability of Sm3+‐activated Sr3La(VO4)3 red‐emitting phosphors

“…When the Sm 3+ ‐activated phosphors are subjected to high temperatures, the 4 G 5/2 level overcomes the energy barrier by absorbing the thermal activation energy and the electrons nonradiatively release to the ground state, leading to the decrement of PL emission intensity . In order to identify the thermal quenching behavior, the activation energy was calculated: …”