Patents Assigned to Adrian H. Kitai
  • Patent number: 5897812
    Abstract: New oxide phosphors based on doped gallium oxides, alkaline earth gallates and germanates for electoluminescent display materials. Bright orange red electroluminescence has been obtained in amorphous and crystalline oxides Ga.sub.2 O.sub.3 :Eu for the first time. SrGa.sub.2 O.sub.4 and SrGa.sub.4 O.sub.9 doped with 1-8 mole % of Eu and Tb, CaGa.sub.2 O.sub.4, Ca.sub.3 Ga.sub.2 O.sub.8 and CaGa.sub.4 O.sub.7 doped with 1-4 mole % of Eu, Tb, Pr and Dy, BaGa.sub.2 O.sub.4 doped with 1-2 mole % of Eu and Tb, have been prepared using RF magnetron sputtering onto ceramic dielectric substrates and annealed at 600.degree. C.-950.degree. C. in air or Ar for 1-2 hours. Bright electroluminescent (EL) emission was obtained with wavelengths covering the visible spectrum from 400 to 700 nm, and infrared emission above 700 nm with spectral peaks characteristic of rare earth transitions. The films of CaGa.sub.2 O.sub.4 with 1 mole % Eu achieved 22 fL (75 cd/m.sup.2) at 60 Hz and had a maximum efficiency of 0.
    Type: Grant
    Filed: November 20, 1997
    Date of Patent: April 27, 1999
    Assignee: Adrian H. Kitai
    Inventors: Adrian H. Kitai, Tian Xiao, Guo Liu
  • Patent number: 5788882
    Abstract: New phosphors based on doped alkaline earth gallates for electroluminescent (EL) display materials. Bright red EL has been obtained in amorphous and crystalline alkaline earth gallates doped with europium. Powder targets of nominal compositions Sr.sub.4 Ga.sub.2 O.sub.7, Sr.sub.7 Ga.sub.4 O.sub.13, Sr.sub.3 Ga.sub.2 O.sub.6, Sr.sub.3 Ga.sub.4 O.sub.9, SrGa.sub.4 O.sub.7, SrGa.sub.12 O.sub.19, Ba.sub.4 Ga.sub.2 O.sub.7, Ba.sub.3 Ga.sub.2 O.sub.6 and Ca.sub.3 Ga.sub.4 O.sub.9 doped with 1-2% Eu, were RF magnetron sputtered onto BaTiO.sub.3 substrates. Both annealed and as-deposited films yielded bright EL emission in the red part of the visible spectrum with peaks characteristic of the Eu.sup.3+ ion.
    Type: Grant
    Filed: January 23, 1997
    Date of Patent: August 4, 1998
    Assignee: Adrian H. Kitai
    Inventors: Adrian H. Kitai, Tian Xiao
  • Patent number: 5725801
    Abstract: New oxide phosphors based on doped gallium oxides, alkaline earth gallates and germanates for electroluminescent display materials. Bright orange red electroluminescence has been obtained in amorphous and crystalline oxides Ga.sub.2 O.sub.3 :Eu for the first time. SrGa.sub.2 O.sub.4 and SrGa.sub.4 O.sub.9 doped with 1-8 mole % of Eu and Tb, CaGa.sub.2 O.sub.4, Ca.sub.3 Ga.sub.2 O.sub.6 and CaGa.sub.4 O.sub.7 doped with 1-4 mole % of Eu, Tb, Pr and Dy, BaGa.sub.2 O.sub.4 doped with 1-2 mole % of Eu and Tb, have been prepared using RF magnetron sputtering onto ceramic dielectric substrates and annealed at 600.degree. C.-950.degree. C. in air or Ar for 1-2 hours. Bright electroluminescent (EL) emission was obtained with wavelengths covering the visible spectrum from 400 to 700 nm, and infrared emission above 700 nm with spectral peaks characteristic of rare earth transitions. The films of CaGa.sub.2 O.sub.4 with 1 mole % Eu achieved 22 fL (75 cd/m.sup.2) at 60 Hz and had a maximum efficiency of 0.
    Type: Grant
    Filed: July 3, 1996
    Date of Patent: March 10, 1998
    Assignee: Adrian H. Kitai
    Inventors: Adrian H. Kitai, Tian Xiao, Guo Liu