Re-dispersible Li+ and Eu3+ co-doped CdS nanoparticles: Luminescence studies

Abstract

Re-dispersible CdS, 5 at.% Eu 3+ -doped CdS, 2 at.% Li + and 5 at.% Eu 3+ co-doped CdS nanoparticles in organic solvent are prepared by urea hydrolysis in ethylene glycol medium at a low temperature of 170 • C. CdS nanoparticles have spherical shape with a diameter of ∼80 nm. The asymmetric ratio (A21) of the integrated intensities of the electrical dipole transition to the magnetic dipole transition for 5 at.% Eu 3+ -doped CdS is found to be 3.8 and this ratio is significantly decreased for 2 at.% Li + and 5 at.% Eu 3+ co-doped CdS (A21 = 2.6). It establishes that the symmetry environment of Eu 3+ ion is more favored by Li-doping. Extra peak at 550 nm (green emission) could be seen for 2 and 5 at.% Eu 3+ co-doped CdS. Also, the significant energy transfer from host CdS to Eu 3+ is found for 5 at.% Eu 3+ -doped CdS compared to that for 2 at.% Li + and 5 at.% Eu 3+ co-doped CdS.

Luminescence Properties of Redispersible Tb3+‐Doped GdPO4 Nanoparticles Prepared by an Ethylene Glycol Route

“…The spectrum consists of many sharp peaks at 274, 312, 352, 368, and 378 nm. The peak at 274 nm corresponds to the 8 S 7/2 Ǟ 6 I 11/2 transition of Gd 3+ , [31] and this peak has the highest absorption relative to the others. It indicates the occurrence of an energytransfer process from the Gd 3+ to the Tb 3+ ion.…”

Mössbauer and magnetic studies on nanocrystalline NiFe2O4 particles prepared by ethylene glycol route

“…Among these methods, co-precipitation approach is an economical and promising ways in the production of fine particles [9]. In our previous studies on luminescence properties of semiconducting oxides and sulphides, it was reported that ethylene glycol could be used as medium as well as capping agent in order to decrease agglomeration among nanoparticles [10][11][12][13]. In this paper we use ethylene glycol as medium as well as capping agent and urea is used for the precipitating agent for the preparation of NiFe 2 O 4 nanoparticles since it can produce NH 4 OH after thermal decomposition.…”

Tuning of ultra-violet to green emission by choosing suitable excitation wavelength in ZnO: Quantum dot, nanocrystals and bulk

“…Ethylene glycol (EG) has peaks at 3212-3495 (broad), 2875, 2939, 1651, 1426, 1051 and 879 cm −1 . A broad peak at 3212-3495 cm −1 is due to the presence of hydrogen bonding among EG molecules (H-O· · ·H-O-) [57][58][59][60][61]. However, stretching frequency of free O-H is at 3650 cm −1 [60].…”