Luminescence in ZnS: (Cu, Tb) and ZnS: (Ag, Tb) phosphors

Abstract

The electro‐, photo‐, thermo‐, and photoelectro‐properties of luminescence in ZnS: (Cu, Tb) and ZnS: (Ag, Tb) phosphors are studied. EL intensity (B) and ac voltage (U) is found to follow a law given by \documentclass{article}\pagestyle{empty}\begin{document}$B = B_0 exp(- b/\sqrt {U)}$\end{document}, where B0 and b are constants. EL and PL spectra of these phosphors are obtained. The phosphorescence decay is found to be in agreement with a monomolecular mechanism. An analysis of the decay curves at different temperatures shows that the trap depth increases slowly with temperature. The trap depth, escape frequency, and capture cross‐section of electrons are calculated using thermal glow curves. The PEL emission of these phosphors is also studied and quenching and enhancement are reported.

Electro‐optical Properties of ZnSe Doped with Gd and (Ag,Gd) Phosphors

“…The ZnS/ZnSe phosphors activated by Ag is one of the best-studied material because of their high efficiency. [2][3][4][5][6]7] Rare earth ions incorporated in ZnS/ZnSe lattice have assumed an added importance by way of providing donor level close to the conduction band. In continuation of our plan to study the electro-optical properties of ZnS/ ZnSe doped with rare earth impurities [8,9,2,4,10] we report here the photo and electroluminescence in ZnSe doped with Gd and (Ag,Gd) phosphors.…”

Synthesis, structural, and optical properties of core/shell ZnS:Fe/ZnS nanocrystals

“…3–5. In recent years, great efforts have been made to study the synthesis of fluorescent ZnS QDs doped with different transition or rare‐earth ions, such as Mn 2+ 6, 7, Cu + 8, 9, Ag + 10, Tb 3+ 11, and Eu 3+ 12. The doping ions act as recombination centers for the excited electron–hole pairs and result in strong and characteristic luminescence.…”

Experiments with Glow-in-the-Dark Toys: Kinetics of Doped ZnS Phosphorescence

“…[See Figure3(bottom) for example.] Second-order kinetics might be expected for a semiconductor with n equal or nearly equal to p.A literature summary(5)(6)(7)(8) indicates that an abrupt drop in brightness (probably exponential) followed by a slow power-law decay, I = a/(t+t o ) b with b in the range of…”