Cornelis Reinder Ronda

Recent achievements in research on phosphors for lamps and displays

Abstract In this paper, the current status of applied luminescent materials is reviewed together with its implication for the performance of devices based on them. In addition, recent developments in the field of luminescent materials for application in lamps and displays are discussed.

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.

Phosphors for lamps and displays: an applicational view

Abstract An overview is given of recent developments in rare-earth-based luminescent materials for application in lamps and displays.

Evidence for exchange-induced luminescence in Zn2SiO4: Mn

Abstract The 4 T 1 → 6 A emission band of Mn2+ in Zn2SiO4: Mn shows a red shift and an increase of the oscillator strength as a function of the Mn2+ concentration. In this paper it is shown that these phenomena are due to exchange interactions between Mn2+ ions.

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

THE DEGRADATION BEHAVIOR OF LAOBR:TB UNDER CATHODE-RAY EXCITATION

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

Near-infrared luminescent nanomaterials for in-vivo optical imaging

Investigations on the degradation behavior of LaOBr:Tb phosphors under cathode‐ray excitation are presented. The microscopic nature of defects created under prolonged electron bombardment has been identified using extended optical analyses on aged LaOBr:Tb phosphor screens and supported by ion desorption experiments performed in an ultrahigh vacuum system. The degradation behavior of LaOBr:Tb can be improved considerably by codoping this phosphor with chloride or iodide.

Optimizing β-Y2SiO5:Tb for projection television applications

Optical imaging using unspecific contrast agents as well as targeted and disease-specific agents play a vital role in preclinical research. Moreover, optical imaging is on the verge of establishing itself as a clinically relevant imaging modality. Also in-vitro diagnostical procedures rely to a large degree on optical labels to report disease-specific events. Materials that fulfill the basic requirements of this market are being used today, with cyanine dyes and semiconductor quantum dots being excellent examples. Other materials are being tested in laboratories throughout the world. Design rules suitable to develop new optical labels for in-vivo near-infrared optical imaging procedures have been formulated by us, and we have developed synthesis routes that lead to nano particles with small diameter, narrow size distribution, high quantum yield, and with stable surfaces required for bioconjugation to disease-specific ligands.

Inorganic Luminescent Materials: 100 Years of Research and Application

Abstract Y 2 SiO 5 :Tb, consisting of spherical grains, has been prepared by recrystallizing Y 2 SiO 5 :Tb in LiF, CsF, BaF 2 or BaCl 2 . Y 2 SiO 5 :Tb, showing no afterglow, has been obtained using LiF and CsF as the fluxing agents. On using CsF as the fluxing agent, Y 2 SiO 5 :Tb was obtained with a cathode-ray efficiency of 40 Lm W −1 .