Red Light Phosphor and Multilayer Photo-Transforming Film

• US 20080290319A1
• Filed: 05/19/2008
• Published: 11/27/2008
• Est. Priority Date: 05/23/2007
• Status: Active Grant

• Current Assignee: Wei-Hung Lo
• Original Assignee: Wei-Hung Lo
• Inventors: TSAI, Chi-Ruei, LO, Wei-Hung, NAUM, Soshchin
• Granted Patent: US 8,007,685 B2
• Time in Patent Office: Days
• US Class Current: 252/301.40S
• CPC Class Codes: C09K 11/779 Halogenides C09K11/7784 takes precedence

Abstract

The present invention relates to a red light phosphor, which is based on sulfide and activating agent containing rare earth strontium or hafnium. It is characterized by that the aforementioned materials are a fluorine-sulfur oxide containing lanthanum-yttrium-zirconium and/or hafnium with its stoichiometric formula as (La_1-x-y-zY_xA_yMc_z⁺⁴O)₂S₁(F⁻¹)_2z, and activating agent based on A=(TR⁺³=Σ Eu, Sm, Gd, Tb)+(TR⁺⁴═Pr⁺⁴), in which Me⁺⁴=Zr⁺⁴ and/or Hf⁺⁴. Compared with standard materials, the luminous intensity of the phosphor according to the present invention is increased to 1.6-2.4 times. Further, the red light phosphor according to the present invention has a mean diameter of d₆₀≈0.6 μm. The present invention also discloses a multilayer photo-transforming film, in which the three-layer agro-film is filled with phosphor. The agro-film is based on polythene and its derivatives and added with photostabilizer.

Claims

1. A red light phosphor, comprising sulfide and activating agent containing rare earth strontium and/or hafnium, which are characterized by that the sulfide is a fluorine-sulfur oxide containing lanthanum-yttrium-zirconium and/or hafnium with overall stoichiometric formula as (La_1-x-y-zY_xA_yMe_z⁺⁴O)₂S₁(F⁻

1)_2z, the activating agent is based on A=(TR⁺³=Σ

Eu·

Sm·

Gd·

Tb)+(TR⁺⁴═

Pr⁺⁴) with Me⁺⁴=Zr⁺⁴ and/or Hf⁺⁴.

2. The red light phosphor as defined in claim 1, wherein the stoichiometric value of the stoichiometric formula, (La_1-x-y-zY_xA_yMe_z⁺⁴O)₂S₁(F⁻

1)_2z, is x=0.001-0.2, y=0.01-0.2, and z=0.001-0.005, respectively.

3. The red light phosphor as defined in claim 1, wherein when the ionic concentration ratio is 0.050<

Eu/(Pr+Sm+Eu+Gd+Tb)≦

0.15, the main radiation wavelength of the phosphor is within the range λ

=615-628 nm.

4. The red light phosphor as defined in claim 3, wherein when the ionic concentration ratio is 0.06<

(Eu+Sm)/Tr⁺³≦

0.095, the excited spectrum of the phosphor is within the ultraviolet wavelength range λ

=320-410 nm.

5. The red light phosphor as defined in claim 1, wherein the mean particle size of the red light phosphor is within the range 0.4≦

d₅₀≦

0.8 μ

m with its largest size no more than d=6-8 μ

m.