- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Highly efficient transparent nanophosphor films for tunable white light-emitting layered coatings
摘要： Bright luminescence in rare-earth (RE) nanocrystals, so-called nanophosphors, is generally achieved by choosing a host that enable the effective excitation of the RE activator through charge or energy transfer. Although tungstate, molybdate or vanadate compounds provide the aforementioned transfer, a comparative analysis of the efficiency of such emitters remains elusive. Herein we perform a combined structural and optical analysis, which reveals that the tetragonal GdVO4 matrix gives rise to the highest efficiency among the different transparent nanophosphor films compared. Then we demonstrate that by sequential stacking of optical quality layers made of Eu3+ and Dy3+ doped nanocrystals, it is possible to attain highly transparent white light emitting coatings of tunable shade with photoluminescence quantum yields above 35%. Layering provides precise dynamic tuning of the chromaticity based on the photoexcitation wavelength dependence of the emission of the nanophosphor ensemble without altering the chemical composition of the emitters or degrading their efficiency. Total extinction of incoming radiation along with the high quantum yields achieved make these thin layered phosphors one of the most efficient transparent white converter coatings ever developed.
关键词： rare-earth nanocrystals,transparent coatings,nanophosphors,phosphor materials,white-light emission
更新于2025-11-14 15:23:50
-
Green and red emitting YBO3:Ln3+ (Ln=Eu, Tb) phosphors for detection of latent fingerprint
摘要： In this paper, we report the synthesis of green and red emitting YBO3:Ln3+ (Ln = Eu, Tb) phosphors through a solvothermal method. The crystal structure of YBO3:Ln3+ (Ln = Eu, Tb) phosphors is well crystallized. The photoluminescence spectra of YBO3:Ln3+ (Ln = Eu, Tb) phosphors exhibit the strong green and red emission. The photoluminescence intensity is increased with increasing Ln3+ ion concentration from 0.01 to 0.07 mol. The latent fingerprints developed on various substrates using YBO3:Ln3+ (Ln = Eu, Tb) phosphors exhibited the highly clear ridge patterns of fingerprints regardless of background interference. Also, the detailed minutiae of fingerprint with different levels can be clearly observed. Therefore, YBO3:Ln3+ (Ln = Eu, Tb) phosphors can be applied to luminescent materials for detection of latent fingerprint.
关键词： Solvothermal,Fingerprint,Phosphor,Optical materials
更新于2025-11-14 15:15:56
-
A novel orange–red emitting phosphor Sr2LuTaO6:Sm3+ for WLEDs
摘要： A novel double perovskite tantalite orange–red light emitting Sr2LuTaO6:Sm3+ phosphor was synthesized by the solid state reaction. The phase, crystal structure, photoluminescence properties, thermal stability and decay curves were studied. The X-ray diffraction patterns indicated that the phosphor has a pure phase of cubic phase structure. Excited by near-ultraviolet light at 407 nm, the sample exhibited three sharp emission peaks at 564 nm, 600 nm, 645 nm corresponding to the 4G5/2 → 6HJ (J = 5/2, 7/2 and 9/2) transitions, respectively. The optimum doping concentration of Sm3+ ions was determined to be 5 mol% and the concentration quenching process comes from the energy transfer among nearest-neighbor ions. The as-prepared phosphors showed excellent thermal stability, the integral intensity at 423 K is about 91.10% of the initial intensity. The CIE chromaticity coordinates of Sr2LuTaO6:Sm3+ phosphors located in orange–red region. The results suggest that Sr2LuTaO6:Sm3+ phosphors have great potential application in white light-emitting diodes.
关键词： luminescence,thermal stability,white light-emitting diodes,Sr2LuTaO6:Sm3+,phosphor
更新于2025-11-14 15:13:28
-
A development of new red phosphor based on europium doped as well as substituted Barium Lanthanum Aluminate (BaLaAlO4: Eu3+)
摘要： New red emitting Eu3+ doped and substituted BaLaAlO4 phosphor powders were synthesized by simple modified solid state reaction method. BaLaAlO4 crystal phase formation studied through powder X-ray diffraction (XRD) analysis. Fourier Transform - Infra Red (FT-IR) analysis was performed to study the formation of the host with respect to temperature increment and metal-oxygen bond vibrations of BaLaAlO4 host lattice. Morphology of the phosphor was appeared as irregular in shapes with agglomeration. Photoluminescence (PL) analysis was performed to study the PL excitation and emission characteristics of the phosphor. It dictates that synthesized phosphors exhibited a strong red emission at 626 nm. Substitution effect of Eu3+ in BaLaAlO4 with various compositions such as Ba(1-x)LaAlO4: Eux3+, BaLa(1-y)AlO4: Euy3+ and BaLaAl(1-z)O4: Euz3+ were studied for PL enhancement. Luminescence decay time of the phosphors was also determined. PL thermal quenching and Commission Internationale de l'Eclairage (CIE) chromaticity analysis were carried out to find thermal stability and colour purity of the phosphor sample respectively. The Judd- Ofelt parameters (Ω2 & Ω4) obtained from the emission spectra of Eu3+ ions in BaLaAlO4 host lattice were evaluated and discussed.
关键词： BaLaAlO4,Eu3+,Red phosphor,Substitution effect,Solid state reaction
更新于2025-11-14 15:13:28
-
Temperature sensitive properties of Eu2+/Eu3+ dual-emitting LaAlO3 phosphors
摘要： In this study, Eu2+/Eu3+ coexisting perovskite LaAlO3 phosphors were synthesized by a traditional high-temperature solid-phase reaction method and investigated via X-ray diffraction data, X-ray photoelectron spectroscopy and temperature-dependent photoluminescence spectra. The Eu2+/Eu3+ coexisting LaAlO3 phosphors exhibit excellent optical temperature sensing characteristics and are potential inorganic materials for temperature detection. The measured maximal absolute temperature sensitivity reaches 0.014 K-1, and the corresponding largest relative temperature sensitivity is 1.193% K-1, which are superior to most of previous reports of that. Meanwhile, the monitored signal peaks are well separated, providing a good signal discriminability. The energy level crossover relaxation of Eu2+ and Struck-Fonger crossover process involving O2–-Eu3+ charge transfer band were used to explain the different temperature-dependent responses of Eu2+ and Eu3+. This work may give new ideas for the future research of optical thermometric materials with high sensitivity and high discriminability.
关键词： Fluorescence intensity ratio,Charge transfer band,Thermometry phosphor,LaAlO3
更新于2025-11-14 15:13:28
-
Large enhancement in upconverted green emission intensity from Ho3+/Yb3+ co-doped Y2Ti2O7 phosphor in the presence of Zn2+
摘要： The Ho3+, Yb3+ co-doped Y2Ti2O7 phosphor samples have been synthesized through solid state reaction method in the absence and presence of Zn2+ ions. The X-ray diffraction (XRD) analysis show that the phase of the crystal is face centered cubic. The zinc free phosphor shows weak upconversion emission in green region due to 5S2, 5F4 →5I8 transition of Ho3+ ion on excitation with 980 nm radiation. The emission intensity is enhanced significantly in the presence of Zn2+ ions due to increase in crystallinity, particle size and asymmetry in the crystal field. We are reporting ~92 times enhancement in the green emission intensity for 30 mol% co-doping of Zn2+ ions. The lifetime of 5S2 level of Ho3+ ion increases by increasing the concentration of Zn2+ ions. The intense green emission in this material may be suitable for display and other fluorescence based devices.
关键词： Upconversion,Y2Ti2O7 phosphor,Zn2+,Green emission,Ho3+ /Yb3+
更新于2025-11-14 14:48:53
-
Enhanced absorption of Sr3Lu2(BO3)4:Ce3+,Tb3+ phosphor with energy transfer for UV-pumped white LEDs
摘要： A series green emission phosphors Sr3Lu2(BO3)4:Ce3+,Tb3+ (denoted as SLBO:Ce3+,Tb3+) with broad absorption band matching well with UV LED chip were synthesized by the solid–state reaction method. The phase and structure were analyzed with XRD, EDX, FT-IR measurements. The energy transfer between Ce3+ and Tb3+ in SLBO was proved by spectra and decay curves detailedly. The emission colors vary from blue to green by adjusting the ratio of Ce3+/Tb3+ doped concentration. With temperature increasing, SLBO:Ce3+,Tb3+ phosphor shows well thermal stability that emission intensity retains 70% of its initial at 25 oC even temperature rising to 150 oC. The internal and external quantum efficiency of SLBO:3%Ce3+,8%Tb3+ are 77.5% and 34.8% under 340 nm excitation, respectively. Combining the as-synthesized SLBO:Ce3+,Tb3+ and red emission phosphor CaAlSiN3:Eu2+ coated on a 365 nm UV chip, a warm white LEDs device with CRI of 83 was achieved. All the results indicate that the SLBO:Ce3+,Tb3+ phosphor has potential application in UV pumped white LEDs.
关键词： phosphor,thermal stability,energy transfer,UV LED
更新于2025-10-22 19:38:57
-
Paintable Room Temperature Phosphorescent Liquid Formulations of Alkylated Bromonaphthalimide
摘要： Organic phosphors have been widely explored with an understanding that crystalline molecular ordering is a requisite for enhanced intersystem crossing. In this context, we explore the room temperature phosphorescence features of a solvent-free organic liquid phosphor in air. Given alkyl chain substitution varied the physical states of bromonaphthalimides, phosphorescence remained unaltered for the solvent-free liquid in air. As the first report, a solvent-free liquid of a long swallow tailed bromonaphthalimide exhibits room temperature phosphorescence in air. Doping of the phosphor with carbonyl guests resulted in enhanced phosphorescence and hence a large area paintable phosphorescent liquid composite with improved lifetime and quantum yield is developed.
关键词： phosphorescence,organic liquids,excimer,luminescent thermometer,liquid phosphor
更新于2025-09-23 15:23:52
-
Enhanced green photoluminescence of erbium doped Zn2SiO4 glass-ceramics as phosphor in optoelectronic devices
摘要： This paper reported the fabrication of Er3+-doped zinc silicate (Zn2SiO4:xEr3+) glass-ceramics using recycle waste glass bottles. The glass-ceramics samples were synthesized with different percentage doping of Er2O3 using conventional melting and quenching method. The structural of α-Zn2SiO4:Er3+ crystal phase and microstructure growth were analysed via X-ray diffraction and field emission scanning electron microscopy, respectively. Fourier transform infrared spectroscopy has confirmed the network structure of α-Zn2SiO4:Er3+ crystal phase. The three excited transition states from UV-visible absorption spectra were enhanced significantly at the states 4F7/2, 2H11/2, 4F9/2. The wide-ranging green emission at around 553-559 nm under excitation 385 nm from α-Zn2SiO4:Er3+ crystal exhibit the energy transition of Er3+ ions from 4S3/2 → 4I15/2. Such luminescence of α-Zn2SiO4:Er3+ based glass-ceramics are probably to have a huge prospective application for glass phosphor devices.
关键词： emission,phosphor,zinc silicate,waste glass,glass-ceramic
更新于2025-09-23 15:23:52
-
Dehydrogenation-driven to synthesize high-performance Lu2Si4N6C:Ce3+- a broad green-emitting phosphor for full-spectrum?lighting
摘要： Green phosphor Lu2Si4N6C:Ce3+ (LSNC:Ce3+) shows an ideal feasibility to the near ultraviolet LED (n-UV LED) for “Full-Spectrum Lighting” (FSL). However, it is complex to synthesize pure Lu2Si4N6C phase. Herein, we prepared LSNC:Ce3+ via a novel dehydrogenation-driven high temperature solid-state reaction method, which distinctly optimized the morphology, and then significantly enhanced the photoluminescent performance of LSNC:Ce3+. The improving mechanism ascribed to the stepwise dehydrogenation of LuH3 which was beneficial to further shear LuH3 particles. The LSNC:Ce3+ phosphor obtained by the optimized process exhibits excellent thermal stability, and its external quantum efficiency is 57.3 %. Interestingly, the intensities of excitation peaks decrease at 375 nm while it increases at 425 nm gradually with the Ce3+ concentration. It is reasonably ascribed to the different ability of photo-ionization in different 5d levels. Finally, the constructed w-LED with the titled phosphor exhibits a well-distributed warm white light with high color rendering index (Ra = 96.6, R9 = 96, R12 = 82). It indicates that the LSNC:Ce3+ gives assistance to compensation for the “spectrum chasm” in blue-green region, as well as contributes to the improvement of Ra and R9, that is beneficial for full-spectrum lighting.
关键词： Carbonitride,n-UV LED,Reaction mechanism,Full-Spectrum,Green phosphor Lu2Si4N6C:Ce3+
更新于2025-09-23 15:23:52