Luminescence Reducing Mechanism of Cd Doped Y2O2S:Ti,Cd Long Afterglow Phosphor

Y1.97-xTi0.03CdxO2S (0≤x≤0.06) phosphors with long afterglow were synthesized by solid-state reaction. The photoluminescence spectra, decay curves, thermoluminescnece spectra and Chromaticity coordinate curves were investigated. Results showed that the luminescence and afterglow intensity of Y1.97-xTi0.03CdxO2S (0≤x≤0.06) reduced gradually with increasing Cd2+ ion content while the shape and position of emission peak remain unchanged. The Chromaticity coordinate of present phosphor keeps at (0.5497,0.4415). Furthermore, based on the results of thermoluminescence curves of Ti, Cd single doped and co-doped Y2O2S phosphors, the doped Cd ion reduces the inherent trap depth of Ti single doped Y2O2S:Ti, and induces simultaneously a new trap level in Y2O2S:Ti,Cd phosphor. Thus, it was proposed that the introduced new structure defect by Cd2+ ions should be responsible for the reducing luminescence and afterglow property.

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Fabrication and Properties of Zinc Silicate Phosphors through Solid State Reaction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.160-162.594 ◽

2010 ◽

Vol 160-162 ◽

pp. 594-598

Author(s):

Guo Jian Jiang ◽

Jia Yue Xu ◽

Hui Shen ◽

Yan Zhang ◽

Lin He Xu ◽

...

Keyword(s):

Solid State ◽

Solid State Reaction ◽

Solid State Reaction Method ◽

Emission Peak ◽

Zinc Silicate ◽

Red Phosphor ◽

Reaction Method ◽

Long Afterglow ◽

Luminescent Mechanism ◽

Silicate Phosphors

Zinc silicate-based (Zn2SiO4:Eu3+) long afterglow phosphors were produced by solid state reaction method. The effects of borax and Eu2O3 additive on the properties of fabricated products have been studied. The results show that, there is not much difference in phase compositions within the borax additive amount; however, their SEM morphologies are different. Borax additive can increase the grain size of the product. Some sintering phenomena could be observed in the sample with Eu2O3 addition. The fluorescence spectroscopy results indicate that, the emission peak of the sample with Eu3+ additive located at 612nm, which may be a good candidate for red phosphor applications. The luminescent mechanism of Zn2SiO4:Eu3+ is also discussed.

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Synthesis and Characterization of Lightweight Beryllium Chloro Silicate Phosphor

10.4018/978-1-7998-7864-3.ch004 ◽

2022 ◽

pp. 89-100

Author(s):

Khushbu Sharma

Keyword(s):

Blue Emission ◽

Emission Peak ◽

Excitation Band ◽

Photoluminescence Spectra ◽

Strong Emission ◽

White Leds ◽

Long Afterglow ◽

Silicate Phosphor ◽

Low Weight

In this chapter, low weight barium-based cholorsilicate Ba5Cl6Si2O6:Eu2+ is prepared through a solid-state reaction. To confirm the structure of the synthesized phosphors, powder photographs were obtained using an x-ray diffractometer. Photoluminescence spectra and FTIR spectra were recorded. Photoluminescence spectra are studied. The emission peak is observed at 407 nm at excitation 275 nm. The intense violet-blue emission is obtained. The broad excitation band and strong emission indicate that Ba5Cl6Si2O6:Eu2+could be a good phosphor candidate for blue LED and white LEDs. Decay curve indicates the phosphor has a long afterglow feature.

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Synthesis and Luminescent Properties of Violet-Ultraviolet Long Afterglow Phosphors

Materials Science Forum ◽

10.4028/www.scientific.net/msf.663-665.170 ◽

2010 ◽

Vol 663-665 ◽

pp. 170-176

Author(s):

Hao Yi Wu ◽

Yi Hua Hu ◽

Yin Hai Wang ◽

Chu Jun Fu ◽

Feng Wen Kang ◽

...

Keyword(s):

Solid State ◽

Oxygen Vacancies ◽

Trap Depth ◽

Luminescent Properties ◽

Solid State Reaction Method ◽

Broad Emission Band ◽

Suitable Model ◽

Reaction Method ◽

Long Afterglow ◽

Broad Emission

The M1.99MgSi2O7: Ce3+0.01 (M: Ba, Sr, Ca) phosphors were prepared by the solid-state reaction method. All the samples emit the violet-ultraviolet light with a broad emission band from about 330 nm to 500 nm. All the phosphors samples show a long afterglow. The strongest afterglow intensity and the longest decay duration of the afterglow come from the Ca1.99MgSi2O7: Ce3+0.01 sample. It is attributed to the suitable trap depth and the high trap concentration of this sample. The traps of these phosphors are induced by the lattice defects. A suitable model involving the cation vacancies and the oxygen vacancies, which act as the hole traps and the electron traps respectively, is proposed.

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Preparation of Long Lasting Phosphor by New Method

MRS Proceedings ◽

10.1557/proc-1074-i10-12 ◽

2008 ◽

Vol 1074 ◽

Author(s):

Hu Jin ◽

Zhu Xiaoqin ◽

Chen Donghua ◽

Wan Kaijun ◽

Guo Yuzhong

Keyword(s):

High Temperature ◽

Solid State ◽

Alloy Powder ◽

Composite Powder ◽

Pure Water ◽

Luminescent Properties ◽

Reaction Velocity ◽

Long Afterglow ◽

Hydrolysis Of ◽

Co Doped

ABSTRACTThe composite powder of Al(OH)3 and Sr(OH)2, was obtained by means of the hydrolysis of the activated Al-Sr alloy powder in pure water. As a precursor, it could be used to prepare long after phosphor Eu, Dy co-doped SrAl2O4 by the modified solid state reaction at 1300°C. The components and microstructure of the composite powder were investigated by XRD, SEM and EDS techniques, and the luminescent characteristics and the afterglow properties of the long afterglow material were also measured at the same time. The experimental results showed that, the distribution of the two elements Al and Sr was uniform in the microstructure of the composite powder, and the contacting surfaces between the solid reactants were increased effectively at high temperature, and the diffusive paths were abbreviated. Therefore, the reaction velocity was increased, the sinter temperature descended and the luminescent properties enhanced.

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Synthesis and blue emission properties of Co-doped CdS semiconductor nanoparticles

Current Applied Materials ◽

10.2174/2666731201666210714095815 ◽

2021 ◽

Vol 01 ◽

Author(s):

Sangaraju Sambasivam ◽

Yedluri Anil Kumar ◽

Chandu V.V. Muralee Gopi ◽

Venkatesha Narayanaswamy ◽

Ihab M. Obaidat

Keyword(s):

Band Gap ◽

Blue Emission ◽

Semiconductor Nanoparticles ◽

Emission Peak ◽

Photoluminescence Spectra ◽

Blue Emission Peak ◽

Cubic Structure ◽

Strong Blue Emission ◽

Xrd And Tem ◽

Co Doped

Background: Cadmium sulfide (CdS) based semiconductors are of great interest for different high-end applications because it poses direct bandgap (2.42 eV). CdS are the primary constituent material in many applications, namely solar cells, electroluminescent, and quantum dot light-emitting diodes. Transition metal-doped CdS revealed considerable influence in the bandgap, photoluminescence properties, and peak energy upon increasing the metal content. Objective: In this work, we study the single-phase cubic structure of CdS. Photoluminescence spectra revealed a strong blue emission peak located at about 445 nm. Methods: We investigate the Co-doping CdS semiconductor nanoparticles prepared via the chemical co-precipitation method using thiophenol as a template, 300 °C/2h in vacuum optimum temperature, and annealing period to yield nanosized particles. Morphology and structural studies of the particles were using XRD and TEM, respectively. Results: XRD and TEM studies for the calcined samples revealed a cubic structure. The crystalline size was in the range of 10-17 nm. Thermo gravimetric analysis (TGA) was employed to stabilize the temperature of annealing for the samples. Photoluminescence spectra revealed a strong blue emission peak around 445 nm, indicating surface states within the band gap region, a characteristic feature of nanoparticles. The blue shift in the spectra and the band gap value of Co-doped CdS nanoparticles was estimated using UV-vis absorption spectra. Conclusion: XRD analysis indicated zinc blende structure, and the intensity decreased with increasing Co content. TEM images show that the particles are spherical with average sizes around 13 nm. Luminescence of the synthesized nanoparticles exhibited blue emission between 400 – 500 nm, with the peak located at about 445 nm. The emission intensity increased with the increase in Co concentration.

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Trap modification and mechanoluminescence improvement by Si substitution for Sn in Sr2SnO4:Sm3+ ceramics

Journal of Advanced Dielectrics ◽

10.1142/s2010135x18500169 ◽

2018 ◽

Vol 08 (03) ◽

pp. 1850016 ◽

Cited By ~ 2

Author(s):

Hua Fang ◽

Gaojian Qiu ◽

Xusheng Wang ◽

Yanxia Li ◽

Xi Yao

Keyword(s):

Stress Response ◽

Solid State ◽

Lattice Distortion ◽

Defect Formation ◽

Trap Depth ◽

Level Energy ◽

Trap Level ◽

Response Range ◽

Stress Sensing ◽

Minimal Stress

A series of Sr[Formula: see text]Sn[Formula: see text]SixO4:0.04Sm[Formula: see text] ([Formula: see text], 0.1, 0.15, 0.2, 0.3, 0.4) were synthesized from solid-state reaction. The mechanoluminescence (ML) performance of Sr[Formula: see text]SnO4:0.04Sm[Formula: see text] was greatly enhanced by partial Si[Formula: see text] substitution for Sn[Formula: see text], and the sample of Sr[Formula: see text]Sn[Formula: see text]Si[Formula: see text]O4:0.04Sm[Formula: see text] showed weaker afterglow and twice stronger ML intensity than that in Sr[Formula: see text] SnO4:0.04Sm[Formula: see text]. The stress response of Sr[Formula: see text]Sn[Formula: see text]Si[Formula: see text]O4:0.04Sm[Formula: see text] ranged from 250 to 1200 N, and its linearity was greatly restored. Particularly, it was very sensitive in the minimal stress response range. These properties of no load threshold for stress sensing and weak afterglow make Sr[Formula: see text]Sn[Formula: see text]Si[Formula: see text]O4:0.04Sm[Formula: see text] superior to other excellent ML materials. The introduction of Si[Formula: see text] caused lattice distortion and promoted defect formation in the system. The trap level energy greatly increased and the trap depth changed, which enhanced the trap ability and therefore improved effectively the ML properties.

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