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Title: Blue photoluminescence in Ti-doped alkaline-earth stannates

Abstract

Blue photoluminescence properties of Ti-doped alkaline-earth stannates, A {sub 2}(Sn{sub 1-} {sub x} Ti {sub x} )O{sub 4} (A=Ca, Sr, Ba) (x=0.005-0.15), were examined at room temperature. These stannates showed intense broad emission bands peaking at 445 nm for Ca{sub 2}SnO{sub 4}, at 410 nm for Sr{sub 2}SnO{sub 4}, and at 425 nm for Ba{sub 2}SnO{sub 4} under UV excitation. Emission intensities were relatively insensitive to Ti concentration and no sharp concentration quenching was observed. Mixing alkaline-earth ions in the crystal structures did not increase the emission intensities in the A {sub 2}(Sn{sub 1-} {sub x} Ti {sub x} )O{sub 4} system. The excitation spectra of these stannates exhibited broad bands just below the fundamental absorption edges, implying that luminescence centers do not consist of the component elements in the host materials. It was suggested that the isolated TiO{sub 6} complexes are possible luminescence centers in these materials, as previously proposed in other Ti-doped stannates such as Mg{sub 2}SnO{sub 4} and Y{sub 2}Sn{sub 2}O{sub 7}. - Graphical abstract: Blue photoluminescence properties of Ti-doped alkaline-earth stannates, A {sub 2}(Sn{sub 1-} {sub x} Ti {sub x} )O{sub 4} (A=Ca, Sr, Ba) (x=0.005-0.15), were examined at room temperature. These stannates showed intense broadmore » emission bands peaking at 445 nm for Ca{sub 2}SnO{sub 4}, at 410 nm for Sr{sub 2}SnO{sub 4}, and at 425 nm for Ba{sub 2}SnO{sub 4} under UV excitation.« less

Authors:
 [1];  [2]
  1. Department of Materials Science, Faculty of Engineering, Kyushu Institute of Technology, 1-1 Sensui, Tobata, Kitakyushu, Fukuoka 804-8550 (Japan)
  2. Department of Materials Science, Faculty of Engineering, Kyushu Institute of Technology, 1-1 Sensui, Tobata, Kitakyushu, Fukuoka 804-8550 (Japan), E-mail: kueda@che.kyutech.ac.jp
Publication Date:
OSTI Identifier:
21015790
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 180; Journal Issue: 4; Other Information: DOI: 10.1016/j.jssc.2007.02.009; PII: S0022-4596(07)00079-5; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION; BARIUM COMPOUNDS; CALCIUM COMPOUNDS; CERAMICS; CRYSTAL STRUCTURE; DOPED MATERIALS; OXIDES; PEROVSKITE; PHOTOLUMINESCENCE; QUENCHING; SPECTRA; STANNATES; STRONTIUM COMPOUNDS; TEMPERATURE RANGE 0273-0400 K; TITANIUM COMPOUNDS

Citation Formats

Yamashita, Takahiro, and Ueda, Kazushige. Blue photoluminescence in Ti-doped alkaline-earth stannates. United States: N. p., 2007. Web. doi:10.1016/j.jssc.2007.02.009.
Yamashita, Takahiro, & Ueda, Kazushige. Blue photoluminescence in Ti-doped alkaline-earth stannates. United States. doi:10.1016/j.jssc.2007.02.009.
Yamashita, Takahiro, and Ueda, Kazushige. Sun . "Blue photoluminescence in Ti-doped alkaline-earth stannates". United States. doi:10.1016/j.jssc.2007.02.009.
@article{osti_21015790,
title = {Blue photoluminescence in Ti-doped alkaline-earth stannates},
author = {Yamashita, Takahiro and Ueda, Kazushige},
abstractNote = {Blue photoluminescence properties of Ti-doped alkaline-earth stannates, A {sub 2}(Sn{sub 1-} {sub x} Ti {sub x} )O{sub 4} (A=Ca, Sr, Ba) (x=0.005-0.15), were examined at room temperature. These stannates showed intense broad emission bands peaking at 445 nm for Ca{sub 2}SnO{sub 4}, at 410 nm for Sr{sub 2}SnO{sub 4}, and at 425 nm for Ba{sub 2}SnO{sub 4} under UV excitation. Emission intensities were relatively insensitive to Ti concentration and no sharp concentration quenching was observed. Mixing alkaline-earth ions in the crystal structures did not increase the emission intensities in the A {sub 2}(Sn{sub 1-} {sub x} Ti {sub x} )O{sub 4} system. The excitation spectra of these stannates exhibited broad bands just below the fundamental absorption edges, implying that luminescence centers do not consist of the component elements in the host materials. It was suggested that the isolated TiO{sub 6} complexes are possible luminescence centers in these materials, as previously proposed in other Ti-doped stannates such as Mg{sub 2}SnO{sub 4} and Y{sub 2}Sn{sub 2}O{sub 7}. - Graphical abstract: Blue photoluminescence properties of Ti-doped alkaline-earth stannates, A {sub 2}(Sn{sub 1-} {sub x} Ti {sub x} )O{sub 4} (A=Ca, Sr, Ba) (x=0.005-0.15), were examined at room temperature. These stannates showed intense broad emission bands peaking at 445 nm for Ca{sub 2}SnO{sub 4}, at 410 nm for Sr{sub 2}SnO{sub 4}, and at 425 nm for Ba{sub 2}SnO{sub 4} under UV excitation.},
doi = {10.1016/j.jssc.2007.02.009},
journal = {Journal of Solid State Chemistry},
number = 4,
volume = 180,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}
  • Semiconductor materials are being used in an increasingly diverse array of applications, with new device concepts being proposed each year for solar cells, flat-panel displays, sensors, memory, and spin transport. This rapid progress of invention outpaces the development of new semiconductor materials with the required properties and performance. In many applications, high carrier mobility at room temperature is required in addition to specific functional properties critical to the device concept. We review recent developments on high mobility stannate perovskite oxide materials and devices.
  • In this paper, we report the obtained strong broadband blue photoluminescence (PL) emission centered at 427 nm for undoped BaZrO{sub 3} observed after 266 nm excitation of submicron crystals prepared by hydrothermal/calcinations method. This emission is enhanced with the introduction of Tm{sup 3+} ions and is stronger than the characteristic PL blue emission of such lanthanide. The proposed mechanism of relaxation for host lattice emission is based on the presence of oxygen vacancies produced during the synthesis process and the charge compensation due to the difference in the electron valence between dopant and substituted ion in the host. Brilliant whitemore » light emission with a color coordinate of (x=0.29, y=0.32) was observed by combining the blue PL emission from the host with the green and red PL emission from Tb{sup 3+} and Eu{sup 3+} ions, respectively. The color coordinate can be tuned by changing the ratio between blue, green and red band by changing the concentration of lanthanides. - Graphical abstract: Strong blue emission from undoped BaZrO{sub 3} phosphor and white light emission by doping with Tb{sup 3+} (green) and Eu{sup 3+} (red) after 266 nm excitation. Highlights: Black-Right-Pointing-Pointer Blue emission from BaZrO{sub 3} phosphor. Black-Right-Pointing-Pointer Blue emission enhanced with Tm{sup 3+}. Black-Right-Pointing-Pointer White light from BaZrO{sup 3+} phosphor.« less
  • Highlights: ► We get a series of Eu{sup 3+} doped tungstate phosphors with a wide range doping level. ► Different doping level leads to different crystal structures of final productions. ► Gd{sub 6}WO{sub 12}-like with a tetragonal lattice structure grows at low doping level. ► Gd{sub 2}WO{sub 6}-like with a monoclinic lattice structure grows at high doping level. ► The doping level at 40 mol% Eu{sup 3+} excited by blue light shows excellent red emission. -- Abstract: A co-precipitation reaction was used to prepare nanocrystal Gd{sub 6}WO{sub 12}:Eu{sup 3+} and Gd{sub 2}WO{sub 6}:Eu{sup 3+} red emitting phosphor powders with differentmore » Eu{sup 3+} doping levels. It is found that under the same preparation conditions, different doping level leads to different crystal structures; Gd{sub 6}WO{sub 12}-like with a tetragonal lattice structure tends to be synthesized at low doping level (10–40 mol%) yet Gd{sub 2}WO{sub 6}-like with a monoclinic lattice structure easily to grow at high doping level (60–80 mol%). The strong red emission of {sup 5}D{sub 0} → {sup 7}F{sub 2} transitions at 620 nm was observed for all powders under either near ultraviolet or blue light excited and the most intense emission was obtained at the concentration of 40 mol%. This kind of powders might find their promising application to compensate the white LEDs for the lack of red light component and to improve rendering index.« less
  • A blue-emitting phosphor of titanium-doped zinc spinel (ZnAl{sub 2}O{sub 4}:Ti; Ti=0–6.0 mol% in relation to Al) nanopowders was prepared by a simple sol–gel method. On annealing at 1000 °C, single-phase ZnAl{sub 2}O{sub 4}:Ti powders had primary particles of 25–30 nm in size and most Ti ions in the form of Ti{sup 4+}. Under UV excitation at 280 nm, a strong and broad blue emission centered at 435 nm was observed. The sources of the excitation and emission were assigned to the charge-transfer excitation and recombination between O{sup 2–}–Ti{sup 4+} and Ti{sup 3+}–O{sup –} ion pairs. Optimum brightness occurred at amore » doping of 2.0 mol% Ti. The decay lifetime of ZnAl{sub 2}O{sub 4}:2%Ti was calculated to be 3.0 ms for the blue emission with CIE coordinates of x=0.168 and y=0.153. The results suggest that ZnAl{sub 2}O{sub 4}:Ti is a promising candidate for application as a blue component phosphor for UV-converting white light-emitting diodes. - Graphical abstract: The absorption band around 270 nm is associated with the charge-transfer processes between octahedral Ti{sup 4+} and O{sup 2−} ions. The excitation band around 280 nm corresponds to the charge-transfer excitations from O{sup 2–}(2p){sup 6} electrons to Ti{sup 4+} (3d{sup 0}). Under 280 nm excitation, the PL spectrum shows a strong blue emission with a peak at around 435 nm. - Highlights: • Single-phase ZnAl{sub 2}O{sub 4}:Ti nanocrystals have been synthesized by a sol–gel process. • Under UV excitation at 280 nm, the blue emission centered at 435 nm is observed. • Blue emission is attributed to a charge-transfer transition involving the Ti{sup 4+} ions.« less
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