Luminescence and Energy Transfer of Eu- and Mn-Coactivated CaAl₂Si₂O₈ as a Potential Phosphor for White-Light UVLED

Abstract

A series of Eu 2+ -and Mn 2+ -coactivated CaAl 2 Si 2 O 8 phosphors have been synthesized at 1400 °C under a reduced atmosphere and their luminescence properties have been investigated as a function of activator and coactivator concentrations. We have discovered that energy transfers from Eu 2+ to Mn 2+ by directly observing significant overlap of the excitation spectrum of Mn 2+ and the emission spectrum of Eu 2+ as well as the systematic relative decline and growth of emission bands of Eu 2+ and Mn 2+ , respectively. The critical distance and average separation of Eu 2+ and Mn 2+ have also been calculated. By utilizing the principle of energy transfer, we have also demonstrated that with appropriate tuning of activator content CaAl 2 Si 2 O 8 :Eu 2+ ,Mn 2+ phosphors exhibit great potential to act as a phosphor for white-light ultraviolet light-emitting diodes (UVLEDs).

Isostructural Metal–Anion Radical Coordination Polymers with Tunable Phosphorescent Colors (Deep Blue, Blue, Yellow, and White) Induced by Terminal Anions and Metal Cations

“…Under the same solvothermal conditions as 1, only yellow polycrystalline samples of [Cd 3 2 ] n (1 a) were obtained without using KCl, whereas yellow polycrystalline samples of [ www.chemeurj.org…”

“…There is growing interest in developing white light-emitting diodes (LEDs) for applications in displays and lighting. [1] White LEDs with multiple emitting components can be subject to energy loss, difficult color balance, and high cost problems; [2,3] however, most of these problems can be overcome by using singlecomponent white-light emissions. It is therefore important to develop single-component white LED materials.…”

A New Class of Nanostructured Inorganic–Organic Hybrid Semiconductors Based on II–VI Binary Compounds

“…They can be produced by a combination of red, green, and blue (RGB) LEDs or by phosphor conversion, in which white light is generated by coating a blue or near-UV LED with a yellow or multichromatic phosphor (200). However, such processes are often associated with complex doping schemes, and, therefore result in significant reduction of device efficiency due to problems such as self absorption, relatively low light capture efficiency of phosphors or nonradiative carrier losses (201)(202)(203). In 2005, Rothanthal and co-workers (72) discovered that very small CdSe nanocrystals ($1.5 nm) are capable of emitting white light by direct conversion of absorbed UV light (as phosphors) without involving a doping process.…”

Optical Properties and Energy Transfer of NaCaPO4:Ce3+,Tb3+ Phosphors for Potential Application in Light‐Emitting Diodes

“…Therefore, the electric dipole-quadrupole interaction predominates in the energy-transfer mechanism from the Ce 3+ to the Tb 3+ ions in NaCaPO 4 :Ce 3+ ,Tb 3+ , which is similar to the results in the literature. [20,30] To further investigate the characteristics of multipolar interactions such as dipole-dipole, dipole-quadrupole, and higher-order interactions, the energy-transfer probability P SA [s -1 ] for each multipolar interaction was considered. [21] The dipole-dipole energy-transfer probability (P SA ) from a sensitizer to an acceptor is given by Equation (5): [12,21] …”