Yinzi Cheng

Effect of the replacement of Zn 2+ with Mg 2+ in Ca 14 Zn 6 Ga 10 O 35: Mn 4+

To obtain applicable red phosphor for plant lighting, a series of Ca14Zn6-xMgxGa9.86O35:0.14Mn4+ phosphors were synthesized by a conventional high-temperature solid-state method. The XRD, SEM, excitation and emission spectra, temperature-dependent emission spectra, decay time, internal quantum efficiency and luminous efficiency are investigated with the change of the doping concentration of Mg2+. The experiment results suggest that the luminescence properties and quantum efficiency of the phosphor can by improved by replacing Zn2+ with Mg2+ at appropriate doses, while the thermal resistance performance and decay time declined, and the internal quantum efficiency and luminous efficiency reached its maximum, when the Mg2+ concentration is 0.40. Ultimately, the appropriate doping concentration of Mg2+ was determined at x = 0.40, in which case, the phosphor has a promising application in future plant lighting.

Tb3+, Eu3+ Co-doped CsPbBr3 QDs Glass with Highly Stable and Luminous Adjustable for White LEDs

Herein, we have introduced rare-earth cations Tb3+ and Eu3+ into CsPbBr3 QDs glass by conventional melt-quenching. Rare-earth cations like Tb3+ emit green light, causing the main peak of bromide lead cesium to exhibit some redshift, owing to the energy transfer between CsPbBr3 and Tb3+. To achieve adjustable light, Eu3+ emits red light, which was doped in this glass with different proportions to solve the problem of red deficiency. More importantly, Tb3+ and Eu3+ co-doped CsPbBr3 QDs glass shows a series of desirable characteristics due to the energy transfer between Tb3+ and Eu3+. Interestingly, the blue light radiated by blue chip can excite Tb3+, Eu3+, and CsPbBr3 perovskite effectively. We acquired high-performance white light-emitting diodes with color-rendering index, color coordinate transformation, and luminous efficiency of 85.7, 4945 K, and 63.21 lm/W under the current of 20 mA. This acquired Tb3+, Eu3+ co-doped CsPbBr3 QDs glass proved the significant feasibility of luminescent materials in solid warm light source.