Photoluminescence Properties of Sm3+-Doped La2O3 Powders

2011 ◽  
Vol 399-401 ◽  
pp. 967-972
Author(s):  
Qi Xiao ◽  
Gao Yuan Zhu
Keyword(s):  
Room Temperature ◽  
Optical Emission ◽  
Precipitation Method ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
Room Temperature Photoluminescence ◽  
Pl Spectra ◽  
Red Phosphors ◽  
Near Ultraviolet ◽  
Forbidden Transitions

The Sm3+-Doped La2O3powders were prepared by precipitation method. The room temperature photoluminescence (PL) spectra of Sm3+-Doped La2O3powders doped with different Sm3+concentration excited at 405 nm have been investigated. The PL spectra showed three main strong emissions peaks at near 572, 613, and 657 nm, which were due to the f-f forbidden transitions of the 4f electrons of Sm3+, corresponding to4G5/2→6H5/2(572 nm),6H7/2(613 nm), and6H9/2(657 nm), respectively. The optimum Sm3+concentration in La2O3powders for optical emission was determined to be 2.0 %. Since the 2% Sm-doped La2O3 offer a rather strong f–f transition excitation in near the UV region, the as-prepared phosphors are likely to be used as potential red phosphors for near-ultraviolet (370-410 nm) light-emitting diodes (LEDs).

Study of Photoluminescence Properties of CuxO Thin Films Prepared by Reactive Radio Frequency Magnetron Sputtering

2015 ◽  
Vol 1792 ◽  
Author(s):  
Jiantuo Gan ◽  
Augustinas Galeckas ◽  
Vishnukanthan Venkatachalapathy ◽  
Heine N. Riise ◽  
Bengt G. Svensson ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Room Temperature ◽  
Quartz Substrate ◽  
Rf Magnetron Sputtering ◽  
Considerable Improvement ◽  
Photoluminescence Properties ◽  
Radio Frequency Magnetron Sputtering ◽  
Room Temperature Photoluminescence

ABSTRACTCuxO thin films have been deposited on a quartz substrate by reactive radio frequency (rf) magnetron sputtering at different target powers Pt (140-190 W) while keeping other growth process parameters fixed. Room-temperature photoluminescence (PL) measurements indicate considerable improvement of crystallinity for the films deposited at Pt>170 W, with most pronounced excitonic features being observed in the film grown using Pt=190 W. These results corroborate well with the surface morphology of the films, which was found more flat, smooth and homogeneous for Pt >170 W films in comparison with those deposited at lower powers.

Room Temperature Photoluminescence Spectra of Annealed PECVD Silicon Nitride Thin Films

1992 ◽  
Vol 284 ◽  
Author(s):  
C. Savall ◽  
E. Bustarret ◽  
J. P. Stoquert ◽  
J. C. Bruyére
Keyword(s):  
Silicon Nitride ◽  
Room Temperature ◽  
Visible Region ◽  
Broad Emission Band ◽  
Isochronous Annealing ◽  
Room Temperature Photoluminescence ◽  
Pl Spectra ◽  
Energy Part ◽  
Pl Spectrum ◽  
Deposited Film

ABSTRACTWe present the changes upon isochronous annealing in the room temperature photoluminescence (PL) spectra of nearly stoichiometric silicon nitride. Samples are prepared by the 50kHz PECVD of a N2/SiH4/Helium gas mixture at 350°C. In the as-deposited films the hydrogen content was around 11% for a refractive index of 1.98. For a photoexcitation at 351 nm, the polarized PL spectrum of the as-deposited film is characterized by a main broad emission band in the visible region with a maximum at 2.55eV. A second narrow peak (FWHM = 55meV), at 3.02eV is observed. We study the evolution of the PL spectra with different isochronous anneals from 350°C to 1000°C. Even though the general shape of the PL spectra does not change, we observe an increase of quantum efficiency with maximum value upon 750°C annealing. Beyond this temperature the low energy part of the PL spectrum shows a slight increase. These variations are compared to those of the infrared absorption peaks measured on the same samples. Both the temperature dependence of the intensity of a well defined absorption peak in the Si-H stretching mode region and that of the PL features can be explained assuming that solid state chemical reactions involving hydrogen and Si-Si bonds occur in the bulk of the alloy.

A novel orange-red phosphor Ca3B2O6:Sm3+, A+(A = Li, Na, K) for white light emitting diodes

2014 ◽  
Vol 07 (03) ◽  
pp. 1450033 ◽  
Author(s):  
Qingbo Liu ◽  
Yufeng Liu ◽  
Fu Yang ◽  
Bing Han ◽  
Hao Feng ◽  
...  
Keyword(s):  
Emission Spectrum ◽  
Integral Intensity ◽  
Red Light ◽  
Red Phosphor ◽  
Light Emitting ◽  
Red Phosphors ◽  
Near Ultraviolet ◽  
Bright Orange ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

A novel orange-red phosphor Ca 3 B 2 O 6: Sm 3+, A+( A = Li , Na , K ) has been synthesized by solid-state reaction at 950°C. The phase purity and photoluminescence (PL) behavior of the phosphor are studied in detail using the powder X-ray diffraction (XRD) technique and PL measurements. Ca 3 B 2 O 6: Sm 3+ phosphor can be efficiently excited by near ultraviolet (n-UV) and blue light, and the emission spectrum consists of four emission peaks at 563, 599, 646 and 709 nm, generating bright orange-red light. When a cation A+ is introduced into Ca 3 B 2 O 6: Sm 3+ as charge compensator, the emission intensity of Ca 3 B 2 O 6: Sm 3+ is evidently enhanced, but the PL spectral profile is unchanged. The integral intensity of the emission spectrum of Ca 2.96 Sm 0.02 Na 0.02 B 2 O 6 excited at 401 nm is about 1.2 times than that of Y 2 O 2 S : Eu 3+ commercial red phosphor. The CIE chromaticity coordinates of Ca 2.96 Sm 0.02 Na 0.02 B 2 O 6 phosphor were (0.608, 0.365), which are close to that of the commercial red phosphors Y 2 O 3: Eu 3+ (0.655, 0.345), Y 2 O 2 S : Eu 3+ (0.622, 0.351) and Sr 2 Si 5 N 8: Eu 2+ (0.620, 0.370).

scholarly journals Near ultraviolet excited Eu^3+ doped Li_3Ba_2La_3(WO_4)_8 red phosphors for white light emitting diodes

2015 ◽  
Vol 6 (1) ◽  
pp. 181 ◽  
Author(s):  
Jie Hu ◽  
Xinghong Gong ◽  
Jianhua Huang ◽  
Yujin Chen ◽  
Yanfu Lin ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Red Phosphors ◽  
Near Ultraviolet ◽  
White Light Emitting Diodes

A novel inequivalent double-site substituted red phosphor Li4AlSbO6:Mn4+ with high color purity: Structure, photoluminescence properties, and application in warm white LEDs

2021 ◽  
Author(s):  
Zhiyuan Li ◽  
Xuhui Zhang ◽  
Ji Wu ◽  
Rui Guo ◽  
Lan Luo ◽  
...  
Keyword(s):  
Rare Earth ◽  
Spectral Properties ◽  
Light Emitting Diode ◽  
Color Purity ◽  
Photoluminescence Properties ◽  
Red Phosphor ◽  
Light Emitting ◽  
White Leds ◽  
Red Phosphors ◽  
High Color Purity

Non-rare-earth Mn4+-doped oxide red phosphors received increasing attention in the white light-emitting diode (LED) field for their admirable chemical stability and spectral properties. Here, a new inequivalent double-site substituted Mn4+-doped...

Facile route to tin oxide containing mesoporous silica composites with room-temperature photoluminescence

2006 ◽  
Vol 21 (3) ◽  
pp. 655-663 ◽  
Author(s):  
Zhicheng Liu ◽  
Hangrong Chen ◽  
Weiming Huang ◽  
Jinlou Gu ◽  
Wenbo Bu ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Tin Oxide ◽  
Room Temperature ◽  
Uv Light ◽  
Treatment Method ◽  
Preparation Temperature ◽  
Strong Emission ◽  
Room Temperature Photoluminescence ◽  
Near Ultraviolet ◽  
Facile Route

In this paper, we report a facile route, the tin vapor treatment method, to prepare tin oxide containing mesoporous silica composites (TOMS), which display room-temperature photoluminescence (RT-PL). Among them, TOMS-1 and TOMS-2 were synthesized from mesoporous silica SBA-15 and KIT-6, respectively. They are composed of amorphous SiO2 and tin oxide species and they display strong emission near ultraviolet (UV) when excited by UV light. By increasing the preparation temperature, their Sn content can be increased and subsequently their photoluminescence (PL) intensities can be greatly enhanced. Besides, their PL properties are revealed to be closely related to 2-fold-coordinated tin oxygen-deficient centers.

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