Effects of Ti4+ Ions on Fluorescence Properties of Sr2CeO4:Sm3+ Phosphors

2016 ◽  
Vol 16 (4) ◽  
pp. 3998-4002 ◽  
Author(s):  
Haiyan Jiao ◽  
Peiyu Wang ◽  
Liwei Liu ◽  
Yuhua Wang
Keyword(s):  
Single Phase ◽  
Charge Transfer Band ◽  
Solid State Reaction Method ◽  
Excitation Band ◽  
Photoluminescence Properties ◽  
Broad Excitation Band ◽  
Light Emitting ◽  
Chromaticity Coordinate ◽  
White Light Emitting Diodes ◽  
Excellent Color

Ti4+-doped Sr2CeO4:Sm3+ phosphors were synthesized with the solid-state reaction method and the effects of doping Ti4+ on the photoluminescence properties were investigated in detail. A broad excitation band ascribed to the O2-–Ce4+ transition was observed in the range of 200 to 400 nm and with doping Ti4+ into Ce4+ sites, the intensity of charge transfer band of O2- →Ce4+ (300–370 nm) was significantly broaden and enhanced. As a result, the emission intensity of Sr2Ce1−xTixO4 has improved about 85% by doping 0.01 mol Ti4+. White emission of −Sr2-yCe0.99Ti0.01O4:ySm3+ at y ≤ 0.03 is due the co-existence of Ce4+ → O2- CT emission and 4G5/2–6HJ Sm3+ transitions whereas only the Sm3+ red emission prevails for 003<y≤0.15. The Sr1.99Ce0.99Ti0.01O4:0.01Sm3+ phosphor exhibited excellent color purity. Its chromaticity coordinate is measured to be (0.326, 0.322), which is close to the pure white (0.33, 0.33). The results showed that Sr1.99Ce0.99Ti0.01O4: 0.01Sm3+ phosphors could be considered as a potential single-phase white-emitting phosphor for white light-emitting diodes.

Photoluminescence properties of single-component white-emitting Ca9Bi(PO4)7:Ce3+,Tb3+,Mn2+phosphors for UV LEDs

2015 ◽  
Vol 3 (27) ◽  
pp. 7096-7104 ◽  
Author(s):  
Kai Li ◽  
Mengmeng Shang ◽  
Yang Zhang ◽  
Jian Fan ◽  
Hongzhou Lian ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
White Light ◽  
Solid State Reaction Method ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
Reaction Method ◽  
White Light Emitting Diodes ◽  
Uv Leds ◽  
Uv Excitation

A series of Ca9Bi(PO4)7:Ce3+,Tb3+,Mn2+phosphors synthesizedviathe high-temperature solid-state reaction method can emit intense tunable color from purple-blue to red including white under UV excitation, which shows their potential application in UV-pumped white-light-emitting diodes.

Synthesis and luminescence properties of new red phosphor YBiW2O9:Eu3+

2017 ◽  
Vol 10 (05) ◽  
pp. 1750066 ◽  
Author(s):  
Zhi Xie ◽  
Wang Zhao ◽  
Wei-Wei Zhou ◽  
Fu-Gui Yang
Keyword(s):  
Internal Quantum Efficiency ◽  
Solid State Reaction Method ◽  
Potential Candidate ◽  
Red Phosphor ◽  
Light Emitting ◽  
Good Thermal Stability ◽  
Near Ultraviolet ◽  
Chromaticity Coordinate ◽  
White Light Emitting Diodes ◽  
First Time

A new series of YBiW2O9:Eu[Formula: see text] phosphors were successfully synthesized by the solid-state reaction method for the first time. Pure phase formation of YBiW2O9:Eu[Formula: see text] was confirmed by X-ray powder diffraction. It is found that the 7F[Formula: see text]L6 transition results in the strongest near-ultraviolet excitation centered at 395 nm and the phosphors show strong electric-dipole (ED) transitions (5D[Formula: see text]F[Formula: see text] with red emission peaking at 616[Formula: see text]nm. The optimal Eu[Formula: see text] doping concentration of 70[Formula: see text]mol.% is presented in YBiW2O9:Eu[Formula: see text] phosphors. The Y[Formula: see text]BiW2O9:0.7Eu[Formula: see text] phosphor has better Commission Internationale de l’Eclairage chromaticity coordinate of (0.669, 0.328) in comparison with commercial red-emitting phosphors (Y2O2S:Eu[Formula: see text], Y2O3:Eu[Formula: see text]. The internal quantum efficiency of Y[Formula: see text]BiW2O9:0.7Eu[Formula: see text] was measured to be 45.1%, and temperature-dependent luminescence shows its good thermal stability. All the results suggest that YBiW2O9:Eu[Formula: see text] is a potential candidate of red phosphor for the applications in white light emitting diodes.

Luminescence Properties of a Novel Blue-Emitting Phosphor NaBaBO3:Tm3+,K+

2015 ◽  
Vol 833 ◽  
pp. 39-43 ◽  
Author(s):  
Jiang Hui Zheng ◽  
Qi Jin Cheng ◽  
Li Li Ying ◽  
Li Han Cai ◽  
Chao Chen
Keyword(s):  
Dipole Interaction ◽  
Solid State Reaction Method ◽  
Concentration Quenching ◽  
Luminescence Properties ◽  
Photoluminescence Intensity ◽  
Quenching Mechanism ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Chromaticity Coordinate ◽  
White Light Emitting Diodes

A novel blue-emitting phosphor NaBaBO3doped with Tm3+was prepared using a conventional high temperature solid-state reaction method. Its crystal structure and luminescence properties were studied. Photoluminescence measurements indicate that the phosphor features a satisfactory blue performance due to the1D2→3F4transition of Tm3+with the highest photoluminescence intensity located at 460 nm excited by 359 nm near-ultraviolet (NUV) light. In addition, the concentration of Tm3+was adjusted in order to obtain the optimum emission intensity. When the Tm3+concentration in NaBaBO3is 6.0 mol% the maximum intensity can be obtained. The concentration quenching occurs when Tm3+concentration is beyond 6.0 mol% and the concentration quenching mechanism can be explained by the dipole–dipole interaction. The measured chromaticity coordinate for the NaBaBO3:Tm3+phosphor under 359 nm excitation is determined to be (0.1470, 0.1090). The present work suggests that the NaBaBO3:Tm3+,K+phosphor is a promising blue-emitting material for NUV white light-emitting diodes.

scholarly journals Multiple Energy Transfer in Luminescence-Tunable Single-Phased Phosphor NaGdTiO4: Tm3+, Dy3+, Sm3+

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1249 ◽  
Author(s):  
Jun Xiao ◽  
Cong Wang ◽  
Xin Min ◽  
Xiaowen Wu ◽  
Yangai Liu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Solid State ◽  
White Light ◽  
Single Phase ◽  
Light Emission ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
Energy Transfers ◽  
White Light Emitting Diodes ◽  
Tunable Emission

Advances in solid-state white-light-emitting diodes (WLEDs) necessitate the urgent development of highly efficient single-phase phosphors with tunable photoluminescence properties. Herein, the Tm3+, Dy3+, and Sm3+ ions are incorporated into the orthorhombic NaGdTiO4 (NGT) phosphors, resulting in phosphors that fulfill the aforementioned requirement. The emission spectrum of Tm3+ ions overlaps well with the adsorption spectra of both Dy3+ and Sm3+ ions. Under the excitation at 358 nm, the single-phase NaGdTiO4: Tm3+, Dy3+, Sm3+ phosphor exhibits tunable emission peaks in the blue, yellow, and red regions simultaneously, resulting in an intense white-light emission. The coexisting energy transfer behaviors from Tm3+ to Dy3+ and Sm3+ ions and the energy transfer from Dy3+ to Sm3+ ions are demonstrated to be responsible for this phenomenon. The phosphors with multiple energy transfers enable the development of single-phase white-light-emitting phosphors for phosphor-converted WLEDs.

scholarly journals Light Output, Thermal Properties, and Reliability of Using Glass Phosphors in WLED Packages

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 239
Author(s):  
Chin-Chuan Huang ◽  
Tsung-Han Weng ◽  
Chun-Liang Lin ◽  
Yan-Kuin Su
Keyword(s):  
Thermal Properties ◽  
Yttrium Aluminum Garnet ◽  
Saturated Vapor ◽  
Light Output ◽  
Junction Temperature ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinate ◽  
White Light Emitting Diodes ◽  
Color Rendering

White-light-emitting diodes (WLED) based on yttrium aluminum garnet (YAG) phosphors sintered with glass (PiG) and with silicone (PiS) are compared in terms of their light properties, temperature properties and reliability.The complete YAG phosphor was doped with an encapsulant traditional WLED (PiS WLED), and the WLED was covered with PiG (PiG WLED). PiG was made by sintering glass powder and YAG phosphor at the ratio of 87:13 (%), and the correlated color temperature (CCT) was 5564 K. The CCT of the PiG WLED with the YAG doping concentration of 8.5 wt.% approximated 5649 K. The initial light output of the PiG WLED was 6.4% lower than that of the PiS WLED. Under 1008 h and 350 mA aging, PiG WLED and PiS WLED’ light output, CCT and color rendering index variation rates were all within 1%. In the saturated vapor-pressure test, no sample exhibited red ink infiltration, light nor peeling between the encapsulant and the lead-frame. Compared with that of the PiS WLED, the junction temperature of the PiG WLED reduced from 88.4 °C to 81.3 °C. Thermal resistance dropped from 37.4 °C/W to 35.6 °C/W. The PiG WLED presented a better CIE (Commission Internationale de l’Eclairage) 1931 chromaticity coordinate (x,y) concentration and thermal properties than the PiS WLED.

A new single-phase white-light-emitting CaWO4:Dy3+ phosphor: synthesis, luminescence and energy transfer

RSC Advances ◽  
2015 ◽  
Vol 5 (77) ◽  
pp. 62527-62533 ◽  
Author(s):  
Yang Zhang ◽  
Weitao Gong ◽  
Jingjie Yu ◽  
Hongchang Pang ◽  
Qiang Song ◽  
...  
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
Single Phase ◽  
Transfer Mechanism ◽  
Energy Transfer Mechanism ◽  
Photoluminescence Properties ◽  
Light Emitting

A new single-phase white-emitting CaWO4:Dy3+ phosphor has been successfully synthesized and the photoluminescence properties and energy-transfer mechanism have been carefully investigated.

scholarly journals Broad near-ultraviolet and blue excitation band induced dazzling red emissions in Eu3+-activated Gd2MoO6 phosphors for white light-emitting diodes

RSC Advances ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 3170-3178 ◽  
Author(s):  
Peng Du ◽  
Yue Guo ◽  
Soo Hyun Lee ◽  
Jae Su Yu
Keyword(s):  
Citric Acid ◽  
White Light ◽  
Light Emitting Diodes ◽  
Sol Gel ◽  
Excitation Band ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Blue Excitation ◽  
White Light Emitting Diodes

A series of Eu3+-activated Gd2MoO6 phosphors were synthesized via a citric acid-assisted sol–gel route.

The Morphologies and Photoluminescence of Ce3+-Doped 0.5La2O3-2SrO-0.5Al2O3 Phosphors with SrF2

2016 ◽  
Vol 680 ◽  
pp. 228-232
Author(s):  
Xi Guang Gu ◽  
Ren Li Fu ◽  
Ye Tang ◽  
Fang Yang
Keyword(s):  
Solid State ◽  
White Light ◽  
Solid State Reaction ◽  
Emission Intensity ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Light Emitting ◽  
Reaction Method ◽  
Reducing Atmosphere ◽  
White Light Emitting Diodes

Ce3+-doped 0.5La2O3-2SrO-0.5Al2O3 (LSA:Ce) phosphors had been successfully synthesized using a conventional solid-state reaction method under reducing atmosphere (H2/N2 =1/5). The phase, morphologies and luminescence properties of the LSA:Ce phosphors were investigated. The emission intensity of LSA:Ce phosphors was improved by the addition of SrF2 as flux, and red shift of PL spectra peak was observed in this phosphors. Research results shown that the LSA:Ce phosphors have the potential to meet the development of white light-emitting diodes.

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