Hans Nikol

New Developments in the Field of Luminescent Materials for Lighting and Displays

Owing to their use in fluorescent lamps and many display applications, luminescent materials affect our daily life. Improvement of already very mature as well as development of new materials demanded by a variety of new applications are the focus of research today. The latest advances in the field of electroluminescence enable new displays and light generation concepts that challenge the classical areas of application of luminescent materials.

Rare-Earth Phosphors: Fundamentals and Applications

In this paper an overview is given of luminescent materials, based on rare earth ions. Fundamental aspects and classical applications of luminescent materials applied in fluorescent lamps and displays are discussed with regard to optical properties. The application potential of rare earth phosphors with regard to new developments such as phosphors for LEDs and luminescent materials with quantum yield larger than unity is also discussed.

Optimization of Luminescent Materials for Plasma Display Panels

Each pixel consists of a discharge chamber with aplasma burning between two sustain electrodes at the frontplate. Ignition and erasing is achieved by an address elec-trode at the back plate (Fig. 1). The pixels are filled with aNe/Xe gas mixture in which, upon ignition, a plasma iscreated emitting vacuum ultraviolet (VUV) light in therange between 140 and 190 nm. This radiation is convertedinto visible light by luminescent materials (phosphors) de-posited on the inner walls of the discharge cells.

Neue Entwicklungen auf dem Gebiet lumineszierender Materialien für Beleuchtungs‐ und Displayanwendungen

In Leuchtstoffrohren und vielen Displayanwendungen begegnen uns lumineszierende Materialien haufig im taglichen Leben. Sowohl die Verbesserung bereits sehr ausgereifter als auch die Entwicklung neuer Materialien fur eine Vielzahl neuer Anwendungen stehen im Zentrum heutiger Forschungsaktivitaten. Die jungsten Fortschritte auf dem Gebiet der Elektrolumineszenz ermoglichen neue Display- und Beleuchtungskonzepte, die Herausforderungen fur die klassischen Anwendungsgebiete von lumineszierenden Materialien sind.

Optimised co-activated willemite phosphors for application in plasma display panels

AbstractProperties, relevant for PDP application, of Mn2 ‘ -activated Zn2SiO4 phosphors non-co-activatedand co-activatedwith Ba2 ‘ ,Cd2 ‘ ,Fe2 ‘ ,Fe3 ‘ ,Al3 ‘ /Li ‘ or Gd3 ‘ /Li ‘ were investigated. For Zn(1.95)Mn0.05SiO4, co-activation withBa2 ‘ and Gd3 ‘ reduces the q10{value at 170 nm excitation from 17 to 10 ms with e

Phosphor screens for flat cathode ray tubes

ciencies still 86% relative tonon-co-activatedZn2SiO4 :Mn2 ‘ .Theq10{ valueincreasesforco-activationwithFe2 ‘ orhighconcentrationofCd2 ‘ .Decay properties were also studied as a function of excitation wavelength. ( 2000 Elsevier Science B.V. All rightsreserved. Keywords: Zinc silicate; Plasma display panels; Mn2 ‘ luminescence; Co-activators 1. IntroductionPhosphors for PDPs need to emit at least 90% oftheir luminescence within the refresh rate of the displayafter excitation by the emission of a Xe/Ne gas dis-charge at 170 nm. The commercial PDP phosphorZn2SiO4:Mn2 ‘ (P1) has a 10% value q10{of 15 mswhichis too long for TV application. In the past, severalattempts were made to improve on the P1 reference. Itwas shown [1,2] that the q10{value can be reduced byincreasingthe Mn2

White light emitting diode

Abstract In the Zeus display panel, as in other flat-panel cathode ray tubes, the anode voltage is limited to a few kV. The effects of the anode voltage on phosphor screen performance are discussed which include energy conversion loss processes at the phosphor surface and variation of the number of luminescent centres available. Phosphor efficiency saturation has been measured in the range of 1 to 10 kV, using a pulse-width-modulation scheme. The luminance performance at different excitation conditions is predicted and confirmed experimentally. Coulomb degradation of phosphor screens is shown to increase with decreasing anode voltage. Novel ultra-thin and dense anti-degradation coatings have been developed for zinc sulphide phosphors which effectively prevent fast degradation due to chemical surface reactions. In this way a satisfactory solution has been found to obtain in the Zeus display a luminance level about equal to the best conventional tubes.