Photoluminescence excitation spectra

In this study, we successfully synthesized europium-doped TiO2 (TiO2 :Eu3+) nanomaterials (NMs) with crystalline sizes ranging from 6.5 to 71.7 nm through a sol-gel method. Analysis of X-ray diffraction (XRD) patterns and ultraviolet-visible (UV-Vis) spectra indicates that the substitution of smaller-sized Ti4+ ions (0.745 Å) by largersized Eu3+ ions (0.947 Å) was more efficient at higher doping concentrations and annealing temperatures.

6p viellison 28-03-2024 3 1   Download

A new host phosphors of LaSr2AlO5 doped with Ce and Eu was synthesized using a solid-state reaction method and the synthesis conditions were investigated. The samples were characterized by X-ray diffraction, scanning electron microscopy, photoluminescent (PL) and photoluminescent excitation (PLE) spectra. LaSr2AlO5:Ce shows a yellow emission at about 570 nm after an excitation at about 450 nm while LaSr2AlO5:Eu presents a red emission.

5p tamynhan9 02-12-2020 15 2   Download

Calcium aluminosilicate (Ca2Al2SiO7) phosphors doped with Ln3+ (1 mol%) ions (Ln: Eu, Ce, and Tb) were prepared by the solid-state reaction at high temperature. Photoluminescence (PL), photoluminescence excitation spectra (PLE) of Ce3+ and Eu3+ ions in Ca2Al2SiO7 material have been studied and used to predict the lowest f-d transition energies as well as charge transfer energies of lanthanides in Ca2Al2SiO7 host lattice.

9p vimississippi2711 08-12-2020 17 0   Download

In this work, Ce3+ and Sm3+ ions doped/co-doped Ca2Al2SiO7 (CAS) phosphors were prepared by solid state reaction method at high temperature. X-ray diffraction results showed that the prepared samples had tetragonal single phases with selected synthesis conditions. Energy transfer process of Ce3+/Sm3+ pair in CAS phosphor was studied by photoluminescence (PL) and photoluminescence excitation (PLE) spectra. Emission intensity of Ce3+ in Ca2Al2SiO7:xCe3+ , (1mol%) Sm3+ phosphors clearly varied with Ce3+ concentration; and reached to maximum value at the concentration of 2 (mol%).

7p caygaocaolon8 07-11-2020 16 1   Download

In this study nanocomposite materials thin films based on poly [2-methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) and nanocrystalline TiO2 (nc-TiO2) have been fabricated. The photoluminescence (PL) spectra of pure MEH-PPV and nanohybrid films have shown that the excitation at a 377 nm wavelength leads to the strongly enhanced performance in photoluminescent intensity due to the compositions of TiO2 component.

6p nguyenxuankha_bevandan 14-08-2020 27 2   Download

The excitation spectra recorded at 300 K on the other hand featured a strong photoluminescence band around 344 nm, which were assigned to the near band-edge absorption transition of ZnS host lattice, in addition with three weaker bands relating to the absorption transitions of [6A1( 6S) → 4T2( 4D)]: 430 nm, [6A1( 6S) → 4A1( 4G) – 4E(4G)]: 468 nm, and [6A1( 6S) → 4T2( 4G)]: 492 nm of Mn2+(3d5 ) cations. It was shown that the capping affected only the intensities of emissions bands.

10p thuyliebe 09-10-2018 29 1   Download

In this paper we report new abnormal photoluminescence results of TiO2 nanocrystal particles and nanotube arrays. Photoluminescence spectra were recorded for TiO2 nanocrystal particles and nanotube arrays that were synthesized by a wet chemical route and the electrochemical anodization, respectively. It was found that the TiO2 nanocrystal with small size of 5-8 nm no emitted when excited by a laser beam of 325 nm, in contrary it emitted when excited by laser beam of 442 nm.

7p thuyliebe 09-10-2018 43 1   Download

ZnS:Mn (CMn = 5 %mol) nanoparticles have been synthesized by a hydrothermal method from solutions of Zn(CH3COO)2 0.1 M, Na2S2O3 0.1 M and Mn(CH3COO)2 0.01 M at 220oC for different reaction time.

5p truongtien_09 08-04-2018 22 1   Download

Zinc aluminate - alumina (ZnAl2O4/Al2O3) systems doped with Cr3+ different concentrations were synthesized by sol-gel method. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The results showed that Cr3+ dopant concentration had a significant effect on the lattice constants of ZnAl2O4/Al2O3 composite and their luminescence characteristics.

7p truongtien_09 08-04-2018 33 3   Download