A new oxyapatite red phosphor Eu3+-doped Ca3Y7(BO4)(SiO4)5O: Synthesis, structure and luminescence properties

Structure, luminescence properties and energy transfer of terbium and samarium co-doped barium based apatite phosphor with tunable emission colour

Ba₂La_2.85-x Tb_0.15Sm _x (SiO₄)₃F (BLSOF:0.15Tb³⁺,xSm³⁺) is a polychromatic phosphor with an apatite structure that was manufactured through a solid-state process. X-ray diffraction (XRD) and a scanning electron microscope (SEM) were utilized to examine the phosphor's phase and morphology. Using the Rietveld technique, the as-prepared phosphor structure was validated. By progressively raising the doping contents of the samarium, the phosphors emitted multicoloured luminescence from short to long wavelengths as indicated by analysis of the optical performance. Overall, the data provide strong evidence that the transfer of energy in BLSOF:0.15Tb³⁺,xSm³⁺ is responsible for the phosphor's colour-tunable property.

Designing bifunctional platforms for LED devices and luminescence lifetime thermometers: a case of non-rare-earth Mn4+ doped tantalate phosphors

Non-rare-earth Mn⁴⁺ doped tantalate (Sr₂GdTaO₆) phosphors exhibiting deep-red emission were synthesized. Afterward, the phase structure, morphology, and optical properties (e.g., emission spectra, concentration quenching, decay curves, thermal stability, quantum yields, etc.) were systematically investigated. Under the optimal conditions, the Sr₂GdTaO₆:0.005Mn⁴⁺ phosphor showed an excellent color purity of 96.41% while the chromaticity coordinates were (0.721, 0.279). Besides, the optimal sample exhibited good thermal stability, and, hence, it can be packaged into light-emitting diode (LED) devices. Red-emitting LED devices could show strong far-red emission and could be suggested for plant cultivation lighting. On the other hand, white-emitting LED devices could find use in indoor illumination. Moreover, with the aid of temperature-dependent lifetime (TDL), a good relative sensing sensitivity (1.73% K^-1 at 453 K) of the luminescent thermometer was established. Herein, all the above findings suggested that Sr₂GdTaO₆:Mn⁴⁺ phosphors are a potential candidate for bifunctional platforms of solid-state lighting and luminescence lifetime thermometers.

Tb3+ and Sm3+ co-doped Ca2La3(SiO4)3F phosphor: synthesis, color regulation, and luminescence properties

The photoluminescence spectra of Ca2La2.85−x(SiO4)3F:0.15Tb3+,xSm3+ phosphors (left) could emit typical multicolor light with increasing doping contents of samarium (right).