Strontium oxyorthosilicate phosphors having improved stability under a radiation load and resistance to atmospheric humidity

• US 8,440,106 B2
• Filed: 03/29/2012
• Issued: 05/14/2013
• Est. Priority Date: 12/21/2009
• Status: Active Grant

• Current Assignee: Litec-LP GmbH, Seoul Semiconductor Co., Ltd.
• Original Assignee: Litec-LP GmbH, Seoul Semiconductor Co., Ltd.
• Inventors: Lee, Chung Hoon, Tews, Walter, Roth, Gundula, Starick, Detlef
• Primary Examiner(s): Le, Emily
• Assistant Examiner(s): EDMONDSON, LYNNE RENEE
• Application Number:
  US13/434,529
• Publication Number:
  US 20120181481A1
• Time in Patent Office: 411 Days
• Field of Search: 252/301.4 R, 252/301.6 R, 252/301.6 P, 252/301.4 P, 252/301.4 H, 252/301.4 F, 313/467, 313/468, 313/503
• US Class Current: 252/301.4F
• CPC Class Codes: C09K 11/77342 Silicates
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source

Abstract

Exemplary embodiments of the present invention relate to inorganic phosphors based on silicate compounds having improved stability under a resulting radiation load and resistance to atmospheric humidity, which are capable of converting higher-energy excitation radiation, i.e. ultraviolet (UV) or blue light, with high efficiency into a longer-wavelength radiation which may be in the visible spectral range. A calcium molar fraction x having a value between 0 and 0.05 is added to a silicate phosphor having the general formula Sr_3-x-y-zCa_xM^II_ySiO₅:Eu_z.

Claims

1. A phosphor, comprising:

a moisture resistant silicate phosphor comprising the formula Sr_3-x-y-zCa_xM^II_ySiO₅;

Eu_z, wherein

M^II is a divalent metal ion comprising at least one of Mg, Ba, Cu, Zn, and Mn;

0<

x≦

0.05;

0<

y≦

0.5; and

0<

z≦

0.25.

2. A phosphor comprising the formula Sr_3-x-y-zCa_xM^II_ySiO₅:

D_z, wherein

M^II is a divalent metal ion comprising at least one of Mg, Ba, Cu, Zn, and Mn;

D is an activator comprising at least one of Eu, Sm, Yb, and Ce;

0<

x≦

0.05;

0<

y≦

0.5; and

0<

z≦

0.25.

3. The phosphor of claim 2, wherein Si in the formula Sr_3-x-y-zCa_xM^II_ySiO₅:

D_z is partially replaced with at least one of Ge, Al, Ga, B, and P.

4. The phosphor of claim 3, further comprising at least one of Li, Na, K, F, CI, Br, and I.

5. The phosphor of claim 2, wherein the phosphor is moisture resistant.