Broadband excited Na₃Tb(PO₄)₂:Ce³⁺/Eu²⁺ green/yellow‐emitting phosphors with high color purity for LED‐based application

Abstract

To enhance the display quality of light-emitting diodes (LEDs), it is great significant to exploit green/yellow-emitting phosphors with narrow emission band, high quantum yield and excellent color purity to satisfy the application. Herein, orthophosphate-based green/yellow emitting Na 3 Tb(PO 4 ) 2 :Ce 3+ /Eu 2+ (NTPO:Ce 3+ /Eu 2+ ) phosphors have been successfully synthesized by a facile solid-state reaction method.The absorption band of NTPO samples was extended to the near ultraviolet region and the absorption efficiency was significantly improved owing to highly efficient energy transfer from Ce 3+ /Eu 2+ ion to Tb 3+ ion in NTPO host certified by time-resolved PL spectra. Upon 300 nm excitation, the NTPO:Ce 3+ is characterized by ultra-narrow-band green emission of Tb 3+ with absolute quantum yield of 94.5%.Unexpectedly, NTPO:Eu 2+ emits bright yellow light with color purity of 73% as a result of the blending of green light emission from Tb 3+ and red light emission from Eu 3+ . The thermal stability has been improved by controlling the stoichiometric ratio of Na + . The prototype white LED used yellow-emitting NTPO:Eu 2+ phosphor has higher color rendering index (Ra = 83.5), lower correlated color temperature (CCT = 5206 K) and closer CIE color coordinates (0.338, 0.3187) to the standard white point at (0.333, 0.333) than that used green-emitting NTPO:Ce 3+ phosphor, indicating the addition of the yellow light component improved the Ra of the trichromatic (RGB) materials.

Lanthanide-doped lead-free double perovskite La2MgTiO6 as ultra-bright multicolour LEDs and novel self-calibrating partition optical thermometer

“…It is further verified that the Ho 3+ /Er 3+ /Tm 3+ -activated LMTO phosphors with higher color purity compared with the previously proposed may have promising applications in white LEDs as a green-emitting or blue-emitting phosphor. 39,40…”

“…It is further verified that the Ho 3+ /Er 3+ /Tm 3+ -activated LMTO phosphors with higher color purity compared with the previously proposed may have promising applications in white LEDs as a green-emitting or blue-emitting phosphor. 39,40 3.4.1 Temperature-sensing properties of Modes I-IV. LIR technology is based on the repopulation of electrons in TCLs or non-TCLs in Ln 3+ ions or transition metal ions.…”

A green emitting (Ba,Ca)ScO2F:Bi3+,K+ perovskite phosphor with high efficiency and good thermal stability for LED backlight displays

“…6b–d, respectively. To further understand the chromatic behaviors of the phosphor, the color purity was calculated according to the following expression: 51,52 …”

Synthesis and photoluminescence of novel blue‐emitting phosphor of Eu2+‐activated fluoroborate BaGaBO3F2

“…Eu 2+ ions typically exhibit broad luminescence transitions strongly depending on their electronic configuration and the crystal field environment, 9 consequentially its luminescence chromaticity changes from ultraviolet to near‐infrared. Eu 2+ has the applications in solid‐state lighting, biomedical imaging, X‐ray fluorescence, plasma display panels, sensors, etc 10–13 . The research on Eu 2+ luminescence has focused on improving the efficiency and stability of Eu 2+ ‐based materials.…”

“…Eu 2+ has the applications in solid-state lighting, biomedical imaging, X-ray fluorescence, plasma display panels, sensors, etc. [10][11][12][13] The research on Eu 2+ luminescence has focused on improving the efficiency and stability of Eu 2+ -based materials. One challenge is achieving high luminescent quantum yields and stability under different environmental conditions.…”