Back to results
US 5,788,883 AGranted
Determination process for determining if quantum splitting phosphors are obtained and novel compositions
AssigneeGeneral Electric Company
InventorsAlok Mani Srivastava, William Winder Beers
Life of this patent
Estimating the term…
Abstract
Quantum splitting phosphors with host lattices activated by praseodymium +3 where covalency of the Pr.sup.+3 -ligand bond is maintained so that the center of gravity of the Pr.sup.+3 4f5d band level is located above the .sup.1 S.sub.0 level and the host lattice has a band gap of greater than about 5 eV.
Claims6
A determination process for determining if quantum splitting phosphors are obtained where a host lattice is activated by Pr.sup.+3, the process comprising the steps of:
- determining if the Pr.sup.+3 is incorporated in the host having an effective coordination number for the Pr.sup.+3 ion so that the Pr.sup.+3 energy position of its 4f5d band is located above a .sup.1 S.sub.0 state;
- determining if the Pr.sup.+3 4f5d band and the .sup.1 S.sub.0 state are positioned below the host lattice conduction band where Pr.sup.+3 is incorporated in a lattice having a band gap greater than about 5 electron volts;
- and
- determining if a site symmetry of the host lattice for the Pr.sup.+3 has been chosen having an effective crystal field strength and an effective Pr.sup.+3 to host lattice bond distance;
- wherein if the Pr.sup.+3 is incorporated in the host having an effective coordination number for the Pr.sup.+3 ion so that the Pr.sup.+3 energy position of its 4f5d band is located above a .sup.1 S.sub.0 state, the Pr.sup.+3 4f5d band and the .sup.1 S.sub.0 state are positioned below the host lattice conduction band, and the site symmetry of the host lattice for the Pr.sup.+3 has been chosen having an effective crystal field strength and an effective Pr.sup.+3 to host lattice bond distance a quantum splitting phosphor is obtained.
2 more elements
Dependencies are inferred from the claim text.