Doped amorphous and crystalline gallium oxides, alkaline earth gallates and doped zinc germanate phosphors as electroluminescent materials
US5725801A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 1996 |
| Grant date | Mar 10, 1998 |
| Priority date | — |
| Expiry date | Jul 3, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B33/10
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
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 0.2 lm/w for red emission. An amorphous thin film of Ca.sub.3 Ga.sub.2 O.sub.6 with 2 mole % Eu achieved 34 fL in red EL at 60 Hz when annealed at 600.degree. C. SrGa.sub.2 O.sub.4 with 1 mole …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.