Structural Confinement toward Giant Enhancement of Red Emission in Mn²⁺‐Based Phosphors

Abstract

Structural confinement effect on a pair of Eu 2+ and Mn 2+ optical centers is developed to realize the greatly enhanced red emission attributed to the 4 T 1 ( 4 G)-6 A 1 ( 6 S) transition of Mn 2+ ions. Sr 9 Mn 1.26(2) Li 0.24(2) (PO 4−δ ) 7 , when it is doped with Eu 2+ , emerges as a new red-emitting phosphor, and the intensity dependence of such a red emission on the trace amounts of Eu 2+ doping is quantitatively analyzed with a combined experimental and theoretical methods. The modeling result confirms the validity of this proposed design strategy, and the intrinsic high-efficient Eu 2+ -Mn 2+ energy transfer process can be elucidated by the structural confinement effect featured as some Sr (Eu) close to Mn atoms. The results can initiate the exploration of Mn 2+ -based red phosphors for pc-white light-emitting diodes applications, and such a strategy can be easily expanded to other systems, thus opening a new perspective for the development of luminescence materials.

Heavy Mn2+ Doped MgAl2O4 Phosphor for High‐Efficient Near‐Infrared Light‐Emitting Diode and the Night‐Vision Application

“…To evaluate the local environments of Mn 2+ , the Mn K‐edge X‐ray absorption near edge structure (XANES) and EXAFS spectra of Mg 1– x Al 2 O 4 : x Mn 2+ ( x = 0.05, 0.10, 0.50, and 1.0) were performed. As shown in Figure a, the XANES spectra of Mn K‐edge for all samples are quite similar, and which are composed of several typical peaks between ≈6500 and 6600 eV, indicating the valence states of Mn in all samples are identical (+2) . Meanwhile, the EXAFS spectra and corresponding fitting data of Mg 1– x Al 2 O 4 : x Mn 2+ ( x = 0.05, 0.10, 0.50, and 1.0) in Figure b and Table S1 (Supporting Information) show that Mn 2+ would only occupy at tetrahedral site in Mg 0.95 Al 2 O 4 :0.05Mn 2+ , whereas that would simultaneously substitute for both tetrahedral and octahedral cations in other samples.…”

Mn2+‐Doped Metal Halide Perovskites: Structure, Photoluminescence, and Application

“…One can find that the commercial phosphors such as Zn 2 SiO 4 :Mn 2+ and BaAl 12 O 19 :Mn 2+ have been widely used, and the Mn 2+ ‐doped II–VI sulfide semiconductors exhibit potential application in the display field. [ 94,108,122–127 ] Figure 1b–j shows the PL of Mn 2+ ions in different coordination environments. Recently, Mn 2+ ‐doped lead halide perovskites become a hot topic, since the presence of Mn 2+ ions provides delightful optical properties.…”

Zero‐Thermal Quenching of Mn2+ Red Luminescence via Efficient Energy Transfer from Eu2+ in BaMgP2O7

“…When applied as red luminescence centers for lighting and displays to improve color rendition and luminous efficacy, however, Mn 2+ emission intensity is generally too low when it is singly doped in the host as a result of the weak 3d‐shell absorption. On the other hand, Eu 2+ ion, with the spin/parity‐allowed 4f→5d transition, has been known as a promising sensitizer to provide an efficient ET to Mn 2+ in many materials . However, severe TQ of Mn 2+ luminescence usually occurs as a result of temperature‐enhanced nonradiative relaxation, and improvement of the luminescence thermal stability remains to be a great challenge .…”