Analysis of room-temperature luminescence spectra of VPE-grown nitrogen-doped gallium phosphide

1975 ◽  
Vol 4 (3) ◽  
pp. 567-590 ◽  
Author(s):  
P. F. Lindquist ◽  
T. L. Larsen
Keyword(s):  
Gallium Phosphide ◽  
Room Temperature ◽  
Luminescence Spectra ◽  
Nitrogen Doped ◽  
Room Temperature Luminescence

Investigations on the Rare Earth Terpyridyl System

1965 ◽  
Vol 20 (6) ◽  
pp. 835-837 ◽  
Author(s):  
Shyama P. Sinha
Keyword(s):  
Rare Earth ◽  
Room Temperature ◽  
Free Ligand ◽  
Ground Level ◽  
Phosphorescence Spectrum ◽  
Rare Earth Ions ◽  
Luminescence Spectra ◽  
Heterocyclic Ligands ◽  
Phosphorescence Lifetime ◽  
Room Temperature Luminescence

The room temperature luminescence spectra of the monoterpyridyl chelates of trivalent samarium, dysprosium and thulium have been studied in solid state by exciting with monochromatic radiation of 3200 Å. The spectra of these chelates show intra f → f fluorescent transitions of the chelated rare earth ions as well as the molecular band fluorescence. The “bottleneck” nature of the energy transfer from the nitrogen containing heterocyclic ligands to the coordinated rare earth ions is proposed. The fluorescence data of mono-terpyridyl chelates have been compared with those of bis-dipyridyl one.The phosphorescence spectrum of terpyridyl has also been investigated. The lowest triplet state of the free ligand is found at 22 940 cm-1 above the ground level. The phosphorescence lifetime of terpyridyl is about 2 sec

Selective Luminescence Spectroscopy of Poly(p-Phenylene) Thin Films at Room Temperature

1995 ◽  
Vol 413 ◽  
Author(s):  
M. A. Drobizhev ◽  
M. N. Sapozhnikov ◽  
V. M. KobryanskII
Keyword(s):  
Thin Films ◽  
Luminescence Spectrum ◽  
Room Temperature ◽  
Selective Excitation ◽  
Luminescence Spectroscopy ◽  
Luminescence Spectra ◽  
Model Calculations ◽  
Localization Threshold ◽  
Low Energy Tail ◽  
Room Temperature Luminescence

ABSTRACTSelectively excited room-temperature luminescence spectra are reported for thin films of poly(p-phenylene) (PPP) deposited onto quartz substrata. The spectra exhibit a localization threshold in the low-energy tail of the luminescence excitation band at vloc.= 22400 cm−1, 2200 cm−1 below the maximum of the excitation spectrum. Upon laser excitation at Vex < Vloc., the maximum Vem of the luminescence spectrum shifts linearly with Vex due to selective excitation of polymer segments. It was found that there exists the frequency range where the slope of the Vem vs Vex dependence is smaller than unity, which corresponds to our previous model calculations for the case of selective excitation of chromophores through broad phonon bands. At vex > vloc,, the luminescence spectrum is independent of Vex. This behavior can be explained if one assumes that upon excitation below the localization threshold the luminescence is related to polymer segments directly excited by laser, whereas upon exciting above the threshold the fast energy relaxation takes place from initially excited states to lower-lying states, from which uminescence occurs.

Activation of Lead Fluoride Room Temperature Luminescence by Structural Modifications

1994 ◽  
Vol 348 ◽  
Author(s):  
D.L. Alov ◽  
A.V. Bazhenov ◽  
V.K. Egorov ◽  
G.A. Emelchenko ◽  
N.V. Klassen ◽  
...  
Keyword(s):  
Room Temperature ◽  
Structural Characteristics ◽  
Structural Defects ◽  
Luminescence Spectra ◽  
Lead Fluoride ◽  
Light Emitting ◽  
X Ray ◽  
Structural Modifications ◽  
Excited Luminescence ◽  
Room Temperature Luminescence

ABSTRACTThe connection of lead fluoride luminescence properties with its structural characteristics has been studied. Single crystals of the cubic and orthorombic phases, cubic and orthorombic powders, pressure compacted orthorombic ceramics, plastically deformed crystals were used. The photo- and X-ray excited luminescence spectra have been investigated. The experimental results have shown that the room temperature luminescence of lead fluoride can be accounted for local light emitting centers which are produced by the intrinsic structural defects in the orthorombic lead fluoride.

Eu3+ Ion Luminescence Spectra from Lanthanide Sesquioxides Exhibiting Three Different Crystal Structures

1992 ◽  
Vol 46 (2) ◽  
pp. 273-276 ◽  
Author(s):  
G. Chen ◽  
R. G. Haire ◽  
J. R. Peterson
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Room Temperature ◽  
Luminescence Spectra ◽  
Spectral Splitting ◽  
The Eu

We have investigated the Eu3+ ion luminescence spectra from different host crystals of the lanthanide sesquioxides exhibiting either the A, B, or C form. The Eu3+ ion luminescence spectra from B-type Eu2O3 and from Eu3+-doped A-type La2O3 and C-type Lu2O3 were obtained at room temperature. It is suggested that the luminescence from f-f transitions in the Eu3+ ion can be used to determine the crystal structure, because the different Eu3+ ion site symmetries in the different crystal structures give rise to different characteristic spectral splitting patterns.

Photoluminescence of Erbium-Diffused Silicon

1996 ◽  
Vol 422 ◽  
Author(s):  
H. Horiguchi ◽  
T. Kinone ◽  
R. Saito ◽  
T. Kimura ◽  
T. Ikoma
Keyword(s):  
Room Temperature ◽  
Crystalline Silicon ◽  
Luminescence Spectra ◽  
Main Peak ◽  
Silicon Substrates ◽  
Annealing Atmosphere ◽  
Full Width ◽  
Half Maximum ◽  
Strong Luminescence ◽  
Fine Structures

AbstractErbium films are evaporated on crystalline silicon substrates and are thermally diffused into silicon in an Ar+02 or H2 flow. Very sharp Er3+-related luminescence peaks are observed around 1.54 μ m.The main peak as well as the fine structures of the luminescence spectra depend on the annealing atmosphere, suggesting different luminescence centers. The full width at half maximum (FWHM) of the main peaks is ≤ 0.5nm at 20K. Thermal diffusion with Al films on top of the Er films is found to increase the intensity of the Er3+-related peaks greatly. The temperature dependence between 20 K and room temperature is relatively small, and a strong luminescence is obtained at room temperature.

Levulinic acid hydrogenation to γ-valerolactone over single Ru atoms on a TiO2@nitrogen doped carbon support

2021 ◽  
Author(s):  
Kaili Zhang ◽  
Qinglei Meng ◽  
Haihong Wu ◽  
Tongying Yuan ◽  
Shitao Han ◽  
...  
Keyword(s):  
Porous Carbon ◽  
Levulinic Acid ◽  
Room Temperature ◽  
Carbon Support ◽  
Complete Conversion ◽  
Turnover Frequency ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

TiO2@nitrogen doped porous carbon dispersed single Ru atom catalyst (Ru/TiO2@CN) efficiently transforms levulinic acid into γ-valerolactone at room temperature in water with a turnover frequency of 278 molGVL molRu−1 h−1 at complete conversion.

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