Fluorescent Display Devices Research Articles

Invariable Cathodoluminescent Intensity of ZnS:Mn Phosphor Operated at Low-Energy Fluorescent Display Devices

Mn-doped ZnS has been studied as a yellow-orange phosphor for the application to fluorescent displays operated at low-excitation energies. It was found that under low-excitation energies (30 eV), the change of luminescence intensity of ZnS:Mn was nearly invariable after second firing or acid treatment of the phosphor. It seems that there is an exchange between conductivity of the phosphor, which is originated from a carbon-induced layer on the phosphor, and the increase of luminescent volume of the phosphor. The luminescence of ZnS:Mn phosphor is affected by addition of conductive material, such as under low-excitation energy and high current density regime. © 2004 The Electrochemical Society. All rights reserved.

Chromophore-functionalized gold nanoparticles.

We report in this Account the design of chromophore-functionalized metal nanoparticles and the detailed investigation of the ground- and excited-state interactions between the metal nanoparticles and the photoactive molecules. The methodologies adopted for organizing chromophore-functionalized gold nanoparticles on two-dimensional surfaces and the mechanistic details of various deactivation channels of the photoexcited chromophores, such as energy and electron transfer to the metal nanoparticle, are presented. The possible applications of such chromophore-functionalized gold nanoparticles in photovoltaics, light-mediated binding and release of biologically important molecules such as amino acid derivatives, and fluorescent display devices are described.

Self Assembled Organizations of Thermotropic Amphiphiles in Molecular Electronics (Synthesis, Characterization and Utility)

Abstract Amphiphilic molecules such as lipids and fatty acids tend to self assemble in micellar organizations when dispersed in aqueous medium. Non-amphiphilic biomolecules having special properties can be incorporated in the matrix of these amphiphiles to achieve molecular level organizates. Alternatively, amphiphilic analogues of desired molecules can be synthesized such that they can exhibit self-assembling properties without affecting their intrinsic special properties. Flavins are strong fluorophores and are known to undergo one/two electron redox reactions. Films made from these molecules can be used to make fluorescent display devices. Amphiphilic analogues of Riboflavin and Flavin Adenine Dinucleotide have been prepared by covalently linking fatty acid chains of varying lengths to native molecule. These molecules have been characterized using NMR, ESR, Optical Spectroscopy, Microscopy, DSC etc. Riboflavin modified with stearate chains was found to possess desirable thermotropic characteristics and...

Electroluminescent Display Materials

Luminescence is the emission of light, other than thermal incandescence, as a result of external stimulation of a material. A material that shows efficient luminescence is called a phosphor. Numerous phosphors have been developed that are important emissive-type electronic display materials for cathode ray tubes, vacuum fluorescent display devices, color plasma display panels, electroluminescent display panels, and, as a matter of course, for fluorescent lamps. Types of luminescence are distinguished by the source of energy input. Photoluminescence involves excitation by optical radiation, cathodoluminescence originates in excitation by electron beam (cathode ray), and e1ectroluminescence is excitation by electric field or current. Luminescence is a subject of deep interest in the field of materials science and for practical application. We are mainly concerned with electroluminescence, especially high-field assisted e1ectro­ luminescence, that is, the light emission obtained by passing electrical excitation energy through a material under an applied high electric field. The main reason for the intensive attention being paid to electro­ luminescent devices, especially to thin film ac electroluminescent devices, is the feasibility of realizing high quality flat panel displays. Thin film ac electroluminescent devices have a multilayered structure of thin films of transparent electrode, insulator, phosphor, and metal electrode. All these are important materials in fabricating an electroluminescent device, and offer numerous topics for research in areas such as electron transport processes and mechanisms of excitation of luminescent centers. In view of the rapid advance in physics and technologies in recent years, it is not possible to give a comprehensive detailed description of