The color point tuning is significant for expanding the application of optical materials (phosphors). In this work, one type of single Eu2+-activated high bright phosphor was prepared, and the color point could be tuned only by controlling the doping level of the activator ion. The phase and crystal structure of the matrix material Y2Mg2Al2Si2O12 (YMAS) were identified and analyzed. The luminescence properties including excitation and emission spectra, peak position attribution, spectral tuning, variation of luminescent intensity, and full width at half-maximum were investigated and explained. The application performance of phosphors and light-emitting diode (LED) devices were tested and discussed. All above results reveal that the YMAS:Eu2+ phosphors can be considered as feasible candidates for ultraviolet LED applications for solid state lighting and backlight display areas.

A series of mesoporous SiO 2 nanoparticles (MSNs) have been synthesized by a modified sol−gel process. The morphology could be manipulated from flower-like nanospheres to flower-like nanodisks, circular nanodisks and sunken nanovesicles by simply adjusting the amount of ammonia. Among the various morphologies, the flower-like nanospheres (N1) with a large specific surface area of 1037.16 m 2 g −1 exhibited the highest and fastest adsorption capacity for dye-RhB because of the most complex surface structure (234.61 mg g −1 , approximately 90% in the first 5 min). The RhB adsorption processes on different MSNs were explained by Langmuir, Freundlich and Temkin isotherm models, and a transition from multilayer adsorption to homogeneous adsorption was achieved. The adsorption kinetics was in accord with the pseudo-second-order model, suggesting the rate-limiting step of RhB on MSNs was mainly chemical process. The luminescence properties of different samples revealed that the nanovesicles structure (N5) exhibited the strongest luminescent intensity due to the least surface defects. By reasonably adjusting the doping concentration ratio of Eu 3+ and Tb 3+ ions, multicolor emissions of red, orange-red, orange, yellow and green can be easily achieved. The excellent adsorption and luminescence performances indicate that the as-prepared multimorphology MSNs have promising applications on efficient wastewater treatment and multicolor optical devices.

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Structure determines properties, and properties determine applications, which is an important ideology of natural sciences. For optical materials, it is vital to lucubrate the corresponding relationship between the local crystal structure and luminescence properties for their design, synthesis, and application. This work reports a newly designed Y2Mg2Al2Si2O12(YMAS):Eu3+ red phosphor, in which difunctional Eu3+ ion is used as a red-light activator and spectroscopic probe. The qualitative and quantitative studies on the relationship between the local crystal structure and the luminescence properties of YMAS:Eu3+ are performed experimentally and computationally, using the Y3Al5O12 (YAG):Eu3+ as contrast. Moreover, compared with YAG:Eu3+, the newly designed YMAS:Eu3+ has stronger luminescence, superior Commission Internationale de L’Eclairage chromaticity coordinates, a lower optimal doping concentration, and equally excellent thermal stability. The satisfactory color-rendering index of packaged white-light-emitting diodes demonstrates its potential performance as a red phosphor. Briefly, this work provides not only a new case for the study of the local crystal structure and luminescence properties but also a new possibility for the application of a red phosphor in solid-state lighting.

A novel luminescence material of emitting color-tunable Ca20Al26Mg3Si3O68 (denoted as CAMSO):Ce3+,Tb3+ phosphors have been synthesized via the high temperature solid-phase reaction process. The crystal cell structure, photoluminescence properties and application performance such as thermal stability and LED device performance of the phosphors were researched in detail. CAMSO:Ce3+,Tb3+ phosphors showed multicolor with the different concentration of Ce3+ and Tb3+ ions. Although the concentration of Ce3+ ions was settled and there was the existence of energy transfer from Ce3+ to Tb3+ ions, it was found that Ce3+ ions’ blue light emission intensity showed abnormal increasing with the increase of Tb3+ ions doping concentration. The irregular phenomenon was discussed in detail. The phosphor CAMSO:0.2Ce3+,0.1Tb3+ photoluminescence emission intensity motivated by 374 nm at 150 °C retained about 81% of that measured at room temperature, which demonstrating the good thermal and color stability of the sample. In addition, the white LED lamps were fabricated through mixing the sample CAMSO:0.2Ce3+,0.2Tb3+ and the commercial phosphor CaAlSiN3:Eu2+ and their performance has been measured. The results show that this series of phosphors could be excellent candidates for the application of UV-excited w-LEDs.