Our work provides a new host lattice K5Y(P2O7)2 for both Eu3+ and Tb3+ luminescence, with non-concentration quenching, a high IQE and good thermal stability.

Developing broad-band-emitting phosphors is very important to light-emitting diode (LED) lighting and displays. We introduced Eu 2+ to solid solutions K 2 YZr 1−y Hf y (PO 4 ) 3 with a langbeinite-type structure to prepare a series of new phosphors. In this structure, two K + sites could be occupied by Eu 2+ cations to provide two different kinds of coordination environments, leading to broad emitting bands in the range of 390−700 nm. The coordination circumstance of Eu 2+ was analyzed by Gaussian fitting and time-resolved emission spectra. Furthermore, the emitting intensity and thermal stability can be improved by modulating the crystalline field via substituting Zr 4+ by Hf 4+ . When the Zr 4+ was fully substituted by Hf 4+ , the external quantum efficiency increased by 53.75%, giving a bright cyan emission. Finally, an archetype white-LED lamp was made using cyan phosphor K 2 YHf(PO 4 ) 3 :0.04Eu, red phosphor CaAlSiN 3 :Eu 2+ , and a 365 nm LED chip, which realized an applicable color rendering index (R a = 81) and a correlated color temperature (CCT = 3792 K).

In the course of preparing Mn-doped phosphors, the mix-valence state of Mn n+ ions may be obtained with associated interesting properties. This work prepared a new phosphor Ba 3 MgSb 2 O 9 :Mn (BMS:Mn) by a traditional high-temperature solid-state synthesis method. In this structure, Mn n+ can replace Mg 2+ site as Mn 2+ oxidation state or Sb 5+ site as Mn 4+ . Moreover, the emitting bands of Mn 2+ and Mn 4+ at around 596 and 758 nm are simultaneously observed by using 350 nm as exciting wavelength. Interestingly, the temperature-dependent emitting intensities corresponding to Mn 2+ and Mn 4+ are different at temperatures from 10 to 300 K. With increasing temperature, the intensity of Mn 2+ luminescence has some enhancement at 10-200 K and then decreases gradually, whereas Mn 4+ luminescence goes into rapid decline. By using this character, BMS:0.01Mn can be used as an optical temperature sensor at 10-300 K based on the fluorescence intensity ratio of Mn 2+ and Mn 4+ . The maximum relative sensitivity (S r ) at 125 K is as high as 1.51% K −1 .

For Mn-activated phosphors, the luminescent performance is strongly dependent on the oxidation state of Mn. In this paper, a series of red phosphors NaMg(PO3)3:xMn2+ (NMP:xMn2+) were synthesized by high temperature...

The Eu2+ ion, with the 4f75d1 electronic configuration, is one of the most important activated ions for its symmetry-allowed 4f→5d electron transition. Herein, we successfully prepared a new type of...