Design of a superb Eu²⁺–Mn²⁺ co‐doped narrow‐band green phosphor via nearly 100% energy transfer efficiency

Abstract

The excellent narrow-band emitters, especially the green ones, are regarded as a pivotal research direction for light-emitting diodes (LED) backlights in liquidcrystal displays (LCDs). A nearly single-peak green emission centered at 513 nm with a full width at half maximum of 28 nm is reached in KAl 11 O 17 :0.1Eu 2+ , 0.15Mn 2+ phosphor via nearly 100% energy transfer (ET) efficiency, and the extended X-ray absorption fine structure analysis elucidates its mechanism, which is that Eu 2+ and Mn 2+ are constrained to form Eu 2+ -Mn 2+ pairs with a small distance 3.7 Å caused by the local environment relaxation inducement. Meanwhile, by creating an unhindered energy flow between Eu 2+ , Mn 2+ and K + /O 2− defect levels through ET and multilevel electron trapped and recombination process, the KAO:Eu 2+ , Mn 2+ phosphors perform superb photoluminescence property with a high color purity of 83%, an excellent thermal stability (94%@200 • C), and unexceptionable internal and external quantum efficiencies of 91.7% and 66.4%, which all are superior to characteristics of commercial β-SiAlON:Eu 2+ phosphor. Moreover, the white LED fabricated using KAO:Eu 2+ , Mn 2+ to provide green component shows a wide color gamut of 105% National Television System Committee. These results indicate a potential for an application of our material in LCD-LED backlights, and the design of such local relaxation-induced structure provides a significative reference to develop the new narrow-band emitters.

Structural and optical properties of Mg1−xMnxP2O6(x = 0–1.0) magnesium metaphosphate

“…Mn 2+ ion has an outer 3d 5 electron configuration, which shows the spin-forbidden 4 T 1 → 6 A 1 transitions in 3d shell. [1][2][3] When Mn 2+ is doped in an octahedral site, it can efficiently give red luminescence ( 4 T 1 → 6 A 1 ) under excitation of near ultraviolet or blue wavelength. Due to the typical d 5 electron configuration, the luminescence properties of Mn 2+ ions are closely related to the crystallographic environment.…”

“…Among the transition metal ions, Mn 2+ is one of the most exciting activators used in luminescence materials. Mn 2+ ion has an outer 3d 5 electron configuration, which shows the spin‐forbidden 4 T 1 → 6 A 1 transitions in 3d shell 1–3 . When Mn 2+ is doped in an octahedral site, it can efficiently give red luminescence ( 4 T 1 → 6 A 1 ) under excitation of near ultraviolet or blue wavelength.…”

Highly efficient blue‐emitting phosphor via charge compensation strategy and its application for white LED lighting

“…These problems can be solved by using the near‐ultraviolet (n‐UV) light pumped WLEDs consisting of red, green, and blue phosphors 13–16 . In this scheme, high‐efficiency phosphors with appropriate excitation and emission spectra are obviously the key components for high‐quality WLEDs 12,17–20 …”

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.…”