[en] Graphical abstract: - Highlights: • A novel red phosphor KBa₂Nb₅O₁₅:Dy³⁺ was synthesized and investigated firstly. • Crystal structure and characteristic luminescence properties are discussed. • The charge compensation mechanism is also investigated. • It has low color tolerance and better CIE chromaticity coordinates. - Abstract: The white light emission phosphor KBa₂Nb₅O₁₅:Dy³⁺ was synthesized by solid-state method. X-ray diffraction (XRD) study reveals that all the Dy³⁺ doped phosphors are single phase. Strong excitation peaks of KBa₂Nb₅O₁₅:Dy³⁺ were found around 380–400 nm, matched well with the NUV LED chip. Under 388 nm excitation, the phosphor exhibited intense white emission by combining the two emission peaks at 477 nm and 572 nm, attributed to the characteristic ⁴F_9/2–⁶H_15/2 and ⁴F_9/2–⁶H_13/2 transition of Dy³⁺. The optimum doping concentration of Dy³⁺ is found to be 3%, whose Commission International de l’ Eclairage (CIE) chromaticity coordinates and correlated color temperature are (0.395, 0.422) and 3925 K, respectively. The results indicate that the KBa₂Nb₅O₁₅:Dy³⁺ phosphor could be considered as a potential candidate for white-LEDs

[en] Micron-sized Ce-doped yttrium aluminum garnet (YAG: Ce³⁺) powders are synthesized successfully by a new method including three processes including solvothermal treatment, precursor preheated and annealing treatment in a mild condition. The phase, morphology and luminescent properties are investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence excitation (PLE) and photoluminescence (PL) spectra respectively. The single-phase sample can be formed after solvothermal treatment at 180 °C for 12 h and annealing at 1200 °C for 4 h. The results obtained by SEM show that the particles with narrow size distribution (∼4 μm) and nice morphology are formed after annealing treatment. This indicates that it has good homogeneity and dispersion. The micron-sized Ce-doped YAG shows broad emission bands in the range of 500–680 nm with the maximum intensity at 577 nm. - Highlights: • Investigate a mild method including three processes to get YAG: Ce³⁺. • YAG: Ce³⁺ was synthesized at lower temperature at 1200 °C. • Obtain better morphology precursor and YAG: Ce³⁺. • Inquiry the effect of the amount of the surfactant to the precursor morphology

[en] CaZr₄(PO₄)₆:Dy³⁺ phosphors have been synthesized by a solid state reaction method. The phosphors were characterized with X-ray diffraction and photoluminescence spectra measurement. Under the excitation of 349 nm, the emission of CaZr₄(PO₄)₆:0.06Dy³⁺ phosphor centered at 487 nm and 577 nm, corresponding to ⁴F_9/2→⁶H_15/2, ⁴F_9/2→⁶H_13/2 transitions of Dy³⁺, respectively. Concentration quenching occurred when the concentration of Dy³⁺ was beyond 6% due to the dipole–dipole interaction by nonradiative energy transfer. The CIE chromaticity coordinates of CZP: 0.06Dy³⁺ phosphor was (0.4219, 0.4322), with CCT (3436 K), which located in the warm white light region. The current results indicated that CaZr₄(PO₄)₆:Dy³⁺ phosphors could be promising candidates for white LEDs. - Highlights: • A new phosphor CaZr₄(PO₄)₆:Dy³⁺ was synthesized and investigated firstly. • Crystal structure and characteristic luminescence properties are discussed. • It can exhibit warm white emission with CIE (0.4219, 0.4322) and low CCT (3436 K)

[en] Graphical abstract: - Highlights: • Novel red phosphor Ca₁₂Al₁₄O₃₂Cl₂:Eu³⁺ was prepared by solid-state reaction. • Excitation spectra suggested an obvious absorption in near-ultraviolet region. • Under 392 nm excitation, the phosphors exhibited a red emission at 614 nm. • Ca₁₂Al₁₄O₃₂Cl₂:Eu³⁺ could be potentially applied in near UV white LEDs. - Abstract: A novel red phosphor Ca₁₂Al₁₄O₃₂Cl₂:Eu³⁺ was synthesized using a solid-state reaction method, and its luminescence characteristics and charge compensators effect (Li⁺, Na⁺, K⁺) were investigated. The excitation spectra showed a obvious absorption in near-ultraviolet region. Under 392 nm excitation, the phosphors exhibited an intense red emission at 614 nm. The Commission Internationale de l’Eclairage (CIE) chromaticity coordinates and quantum efficiency (QE) were (0.65, 0.35) and 62.3%, respectively. The good color saturation, high quantum efficiency and small thermal-quenching properties indicate that Ca₁₂Al₁₄O₃₂Cl₂:Eu³⁺ could be potentially applied in near UV white light-emitting diodes

[en] A series of Dy³⁺ doped Ca₁₉Mg₂(PO₄)₁₄ phosphors were firstly synthesized by the solid-state reaction method. The phase purity and characteristic luminescent properties are investigated in detail by X-ray diffraction refinement, photoluminescence spectra and decay times measurement. Under 365 nm excitation, Ca₁₉Mg₂(PO₄)₁₄:Dy³⁺ phosphor can exhibit intense warm white emission with CIE chromaticity coordinates (0.400, 0.452) and low correlated color temperature (3994 K). The optimal doping contents of Dy³⁺ in Ca₁₉Mg₂(PO₄)₁₄ is determined to be 2%. The thermal quenching property of Ca₁₉Mg₂(PO₄)₁₄:Dy³⁺ is also investigated and it remains 60% of the initial emission intensity even when the temperature increases to 230 °C. The results show that Ca₁₉Mg₂(PO₄)₁₄:Dy³⁺ can be a promising single phased white emitting phosphor for UV white LEDs. - Highlights: • A series of Dy³⁺ doped CMP phosphors were successfully synthesized. • The phase purity and characteristic photoluminescence properties were investigated. • CMP:Dy³⁺ phosphor exhibits warm white emission with CIE (0.400, 0.452) and low CCT (3994 K). • CMP:Dy³⁺ phosphor has good thermal stability

[en] A new Ca₂La₈(GeO₄)₆O₂ (CLGO) compound has been synthesized via solid-state reaction process for the first time. The crystal structure of CLGO was refined and determined by Maud Program. The photoluminescence spectra (PL), cathodoluminescence spectra (CL), and lifetimes as well as temperature dependence of photoluminescence of CLGO:RE³⁺ (RE³⁺=Eu³⁺, Tb³⁺, Dy³⁺, Sm³⁺, Tm³⁺) were investigated in detail. Under the excitation of ultraviolet, CLGO:RE³⁺ (RE³⁺=Eu³⁺, Tb³⁺, Dy³⁺, Sm³⁺, Tm³⁺) show red, green, yellow, orange, violet emission, respectively. -- Highlights: • A new Ca₂La₈(GeO₄)₆O₂ (CLGO) compound has been synthesized for the first time. • The crystal structure of CLGO has been refined by Maud refinement method. • Photoluminescence spectra of CLGO:RE³⁺ were firstly investigated

[en] Objective: To explore whether antisense-EGFR could enhance the radiosensitivity of human lung cancer spc-a-1 cell line. Methods: The spc-a-1 cells were transfected with antisense-EOFR-pcDNA3 by lipolectamine 2000 (pcDNA3 antiEGFR group). Two other groups were used for comparison: control group (spc- a-1 cell without transfection) and pcDNA3 group (spc-a-1 cell transfected with pcDNA3 which did not contain antisense EGFR). Cell clones that stable expressing antisense-EGFR was selected with G418 and the suppression of the expression of EGFR mRNA and protein were detected by RT-PCR and Western blot. The influence of antisense-EGFR on cell cycle was testified by flow cytometry assay. The cell apoptosis was analyzed by flow cytometry after 8 Gy irradiation. Further, cells of each group were irradiated with X-rays at the dose of 0, 2, 4, 6 and 8 Gy. Dose-survival curve of each group was established by colony-forming assay. Results: The expression of EGFR mRNA and protein were significantly inhibited after antisense-EGFR- pcDNA3 transfection. The cells arrested at the G₂/M phase in the pcDNA3 antiEGFR group, control group and pcDNA3 group were (29.53±1.91)%, (13.7±1.30)% and (12.40±1.34)%, respectively. The apoptosis index of spc-a-1 cells in the antisense-EGFR combined with irradiation group was obviously higher than that of the comparable groups [(39.24±1.57)%, (13.79±0.63)% and (15.02±0.85%)]. The values of D₀, D_q, SF₂ of pcDNA3 antiEGFR group declined obviously compared with the control group(2.11, 2.49, 0.84 vs 1.19, 0.15, 0.32). Conclusions: Antisense-EGFR could induce the G₂/M cell cycle arrest, promote cell apoptosis and inhibit the ability of sublethal cell damage repair induced by irradiation, so that it could significantly improve the radiosensitivity of spc-a-1 cell in vitro. (authors)

[en] A series of Sr₉Mg_1.5(PO₄)₇:Tm³⁺, Dy³⁺ phosphors were prepared by conventional sintering method. Rietveld refinement, X-ray diffraction patterns, PL/PLE spectra, lifetimes and thermal quenching spectra were measured and investigated in detail. All the prepared phosphors crystalized to single phase and consisted of micronized particles. When excited by 358 nm, the emission hue of Sr₉Mg_1.5(PO₄)₇:0.01 Tm³⁺, yDy³⁺ (0 ≤ y ≤ 0.20) turned from blue to white by modifying the Tm³⁺/Dy³⁺ ratio. The overlapped PL/PLE spectra and decreasing lifetimes of Sr₉Mg_1.5(PO₄)₇:Tm³⁺, yDy³⁺ indicated the energy transfer from Tm³⁺ to Dy³⁺. Moreover, the resonance type energy transfer from sensitizer (Tm³⁺) to activator (Dy³⁺), CIE chromaticity and energy transfer efficiency were confirmed and discussed, too. The energy transfer mechanism was determined as a resonant type via dipole-dipole mechanism with 53.05% energy transfer efficiency when the doping content y = 0.02. The CIE chromaticity coordinates of Sr₉Mg_1.5(PO₄)₇:0.01 Tm³⁺, 0.20Dy³⁺ was (0.3279, 0.3299) with 27.8% quantum efficiency. The sample also exhibited excellent thermal quenching performance with the remained 95% emission intensity at 150 °C compared with the original emission intensity at ambient temperature. The outstanding luminescence properties and excellent thermal stability suggested that Sr₉Mg_1.5(PO₄)₇:0.01 Tm³⁺, 0.20Dy³⁺ phosphor had a potential application in WLEDs.

[en] Highlights: • Sr₉Mg_1.5(PO₄)₇: Sm³⁺ phosphor was successfully synthesized and investigated. • We reconsider the Sr₉Mg_1.5(PO₄)₇ structure and coordination numbers of Sr²⁺ ions. • Sr₉Mg_1.5(PO₄)₇: Sm³⁺ phosphor can exhibit small thermal quenching performance. -- Abstract: A series of novel orange-red phosphors Sr₉Mg_1.5(PO₄)₇: xSm³⁺ were synthesized by high temperature sintering method. Rietveld refinement, X-ray diffraction patterns, photoluminescence spectra, decay times and luminescence spectra showing thermal quenching were measured and investigated in detail. The mechanism of interaction for energy transfer, CIE chromaticity coordinates and color purity of the phosphors were studied and discussed, too. According to the Rietveld refinement, the coordination numbers of Sr²⁺ were reconfirmed based on the refined structure for the first time. Moreover, it was found that under near-ultraviolet excitation, Sr₉Mg_1.5(PO₄)₇: xSm³⁺ exhibited an intense orange-red emission centering at 598 nm and 650 nm which can be assigned to ⁴G_5/2 to ⁶H_7/2 and ⁶H_9/2 energy level transitions of Sm³⁺, respectively. The CIE chromaticity coordinates of Sr₉Mg_1.5(PO₄)₇: 0.2Sm³⁺ was (0.6066, 0.3923) with outstanding color purity of 98.8%. The sample also exhibited good thermal quenching properties with the remained 70% emission intensity at 150 °C compared with that at ambient temperature. Furthermore, in order to further improve the luminescent intensity and the thermal stability, Li⁺, Na⁺ and K⁺ were incorporated into Sr₉Mg_1.5(PO₄)₇:0.2Sm³⁺ as the compensator charges. Among all the samples with compensator charges, Sr₉Mg_1.5(PO₄)₇:0.2Sm³⁺, 0.2Na⁺ presented the highest emission intensity and best temperature quenching properties because of the similar radius of Na⁺ and Sr²⁺. The improved and linear thermal stability and strong luminescence intensity suggested that Sr₉Mg_1.5(PO₄)₇:0.2Sm³⁺, 0.2Na⁺ has a potential use in solid-state lighting.

[en] Highlights: → NCSE phosphors can be efficiently excited by ultraviolet light. → The PL integral intensity of NCSE excited at 393 nm is 1.87 times of Y₂O₃:Eu³⁺. → NCSE phosphors have good color saturation and high quantum efficiency. -- Abstract: Novel red phosphors Na₂CaSiO₄:xEu³⁺ were synthesized using high temperature solid-state reaction and their luminescence characteristics were investigated for the first time. The excitation spectra indicate that the Na₂CaSiO₄:xEu³⁺ phosphors can be effectively excited by ultraviolet (393 nm) light. The emission spectra of Na₂CaSiO₄:xEu³⁺ phosphors invariably exhibit four peaks assigned to the ⁵D₀-⁷F_J (J = 1, 2, 3 and 4) transitions of Eu³⁺ under 393 nm excitation. The Commission Internationale de l'Eclairage (CIE) chromaticity coordinates and quantum efficiency (QE) are (0.66, 0.34) and 58.9%, respectively. The good color saturation and high quantum efficiency indicate that Na₂CaSiO₄:Eu³⁺ phosphors are potential candidate for light-emitting diodes.