One-Dimensional Fluorescent Silicon Nanorods Featuring Ultrahigh Photostability, Favorable Biocompatibility, and Excitation Wavelength-Dependent Emission Spectra

2016 ◽  
Vol 138 (14) ◽  
pp. 4824-4831 ◽  
Author(s):  
Bin Song ◽  
Yiling Zhong ◽  
Sicong Wu ◽  
Binbin Chu ◽  
Yuanyuan Su ◽  
...  
2016 ◽  
Vol 675-676 ◽  
pp. 376-379 ◽  
Author(s):  
Narun Luewarasirikul ◽  
Piyachat Meejitpaisan ◽  
Jakrapong Kaewkhao

Lanthanum calcium phosphate glasses doped with Eu3+ ions in compositions 20La2O3:10CaO:(70-x)P2O5:xEu2O3 (where x = 0.05, 0.10, 0.50 and 1.50 mol%) were prepared by melt-quenching technique. The density and molar volume measurements were carried out at room temperature. The absorption spectra were investigated in the UV-Vis-NIR region from 200 to 2500 nm. The emission spectra of Eu3+-doped glasses centered at 590 nm (5D0→7F1), 612 nm (5D0→7F2), 652 nm (5D0→7F3) and 699 nm (5D0→7F4) have been observed with 393 nm excitation wavelength.


2010 ◽  
Vol 9 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Xupeng Hu ◽  
Rongguo Su ◽  
Fang Zhang ◽  
Xiulin Wang ◽  
Hongtao Wang ◽  
...  

2019 ◽  
Vol 10 (1) ◽  
pp. 315
Author(s):  
Yunan Chen ◽  
Ruifang Yang ◽  
Nanjing Zhao ◽  
Wei Zhu ◽  
Yao Huang ◽  
...  

Developing fast and accurate fluorescence detection technology of oil spill is significant for quantitative analysis in unexpected oil spill events. As the oil sample concentration increases, the fluorescence spectrum produces red-shift behavior, which seriously affects the quantitative detection of concentration. In this work, a three-dimensional concentration-emission matrix (CEM) was constructed by using a series of emission spectra with different levels of concentration at the excitation wavelength of 266 nm. The database is the interpolated CEM of six samples using bicubic interpolation in the concentration dimension. With matrix similarity matching, the database was used to achieve quantification of the concentration of oil samples. The recovery rates of prediction for test samples and weathering samples of six oil samples were between 86.8% and 116.11%, with relative errors of predictions ranging from 2.09% to 15.2%. The results show that this method can provide accurate quantitative determination of the concentration of different oil samples.


2013 ◽  
Vol 22 ◽  
pp. 336-339
Author(s):  
M. H. MANGROLA ◽  
V. G. JOSHI ◽  
B. H. PARMAR ◽  
A. S. PILLAI

In the present study, Strontium doped Titanium Dioxide (TiO2) were synthesized by standard solid-state reaction technique. The dielectric property of the synthesized samples has been studied in the present work. The dielectric constant and loss have been measured as a function of frequency (100 Hz-1 KHz) and temperature (50°C to 300°C). Strontium doped TiO2 shows interesting optical properties promising a variety of optical applications. Photoluminescence (PL) spectra was obtained at different excitation wavelength. PL emission spectra show that positions of PL peaks gradually shifts towards the violet region with increase of Sr ion dosage from 3% to 5%. The results are discussed in details.


2006 ◽  
Vol 94 (5) ◽  
Author(s):  
Isabelle Billard ◽  
Gilles Montavon ◽  
Sandrine Markai ◽  
Catherine Galindo

SummaryIn the case of a rapid photochemical process, a new theoretical result relating time-resolved emission spectroscopy data to three physical parameters of the chemical system has been recently proposed. This previous work, based on a simulation study, is experimentally evidenced in the present paper, using europium/acetate as a model system. The comparison of the emission spectra obtained upon direct excitation of europium (394 nm) and by use of the “antenna effect” (266 nm) evidences the occurring of a back-dissociation of excited europium complexes to form solvated excited free europium ions.


2004 ◽  
Vol 817 ◽  
Author(s):  
Yu-Feng Lin ◽  
Yen-Hwei Chang ◽  
Bin-Siang Tsai

AbstractRed light emitting of Mn2+ doped Ba2ZnS3 phosphor powders have been synthesized by double-crucible method at different thermal treatments. XRD results indicate that the raw materials are completely sulfurized above 950°C, and the Ba2ZnS3: Mn2+ powders don't change its orthorhombic crystal structure with increasing doping concentration from 0 to 0.8 mol%. The photoluminescence of Ba2ZnS3: Mn2+ powders fulfilled the most efficient emission at the excitation wavelength λex=358 nm and showed the red emission light with peak wavelength λem=627nm at the doping concentration of Mn2+ ion between 0.2 and 0.8 mol%. The high-luminance red emission results from the 4T1 (4G)—6A1 (6S) transition in the Mn2+ ion. Ba2ZnS3: Mn2+ phosphors synthesized by double-crucible method have broad emission spectra (550nm∼750nm) with FWHM (full width at half maximum broadband) about 66nm. In our research, the Ba2ZnS3 doped with 0.4 mol% Mn2+ has the highest luminescent intensity as thermal treatment at 950°C for 16 hours and the CIE coordinate is x=0.66, y=0.33.


2016 ◽  
Vol 705 ◽  
pp. 204-208
Author(s):  
Siti Nasuha Rafien ◽  
Azman Kasim ◽  
Azhan Hashim ◽  
S. Akmal Syamsyir ◽  
Mardhiah Abdullah ◽  
...  

Tellurite glasses were generally applied in rare earth optical materials due to their excellent in physical and chemical properties. In this study, tellurite glasses composed of (70-x)TeO2-20B2O3-10ZnO-xSm2O3 (x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) were prepared by conventional melt-quenching technique. Some basic physical parameters such as density, molar volume and oxygen packing density as well as the optical analysis by mean of their absorption and emission spectra have been carried out at room temperature using UV/Vis and photoluminescence spectrophotometer. The result of physical properties are found to vary with respect to concentration of Sm3+ ions content. Meanwhile, three strong absorption peaks are observed and are well resolved in the ultra violet and visible regions due to transitions between the ground state and various excited state of Sm3+ ions. Under 480nm laser excitation, luminescence spectra exhibit four emission bands at 562 nm, 599 nm, 645 nm and 706 nm which corresponding to the transition 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 were observed. Some other results were also been analysed and presented.


2003 ◽  
Vol 58 (7-8) ◽  
pp. 411-418
Author(s):  
A. Kawski ◽  
B. Kukliński ◽  
P. Bojarski

The effect of the time of irradiation with the excitation wavelength λexc on the absorption and emission spectra of p-cyano-N,N-dimethylaniline (CDMA), p-cyano-N,N-diethylaniline (CDEA) and N,N- dimethylaniline (DMA) in acetonitrile and in n-hexane, as well as the effect of high temperature is studied. It is found that after sufficiently long irradiation of CDMA and CDEA in acetonitrile the short wavelength SE band intensity strongly increases compared to that of the long wavelength LE band. This phenomenon is caused by the photolysis of CDMA and CDEA in polar solvents. In each case both the irradiation time and the delivery of suitable thermal energy leads to irreversible processes. Investigations of the λexc effect on the location and intensity distribution of emission bands have shown their independence of λexc ranging from 260 nm to 330 nm in the LE band. However, a pronounced effect of λexc on the intensity appears in the SE band. In this spectral region DMA molecules formed due to the photolysis of CDMA absorb strongly. Excitation at λexc = 340 - 360 nm in the dimeric absorption band leads to a new emission band overlapping the LE band, which indicates the presence of luminescing dimers.


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