Phosphor compositions and short wavelength infrared emitting pcLEDs emitting in the 1600-2200 nm wavelength range
A wavelength converting structure is provided, the wavelength converting structure including an SWIR phosphor having emission wavelengths in the range of 1600-2200 nm, the SWIR phosphor comprising a structurally disordered garnet material, a sensitizer ion, and at least one rare earth emitter ion. Also provided is a luminescent material having emission wavelength in the range of 1600-2200 nm, the luminescent material including (Gd 3−u−v−x−y−z Lu x Tm y Ho z Sc v RE u )[Sc 2−a−b Lu a Cr b Ga d Al e ]{Ga 3−c Al c }O 12 with RE=La, Y, Yb, Nd, Er, Ce and 0≤u≤2, 0<v≤1, 0<x≤1, 0<y≤0.5, 0≤z≤0.05, 0<a≤1, 0<b≤0.3, 0≤c≤3, 0<d≤1.8, 0≤e≤1.8. An IR emitting device including the luminescent material may provide a broad-band emission in the wavelength range of 1600-2200 nm with a continuous emission spectrum over a spectral width of at least 500 nm.
1. A wavelength converting structure comprising an SWIR phosphor having emission wavelengths in the range of 1600-2200 nm, the SWIR phosphor comprising a structurally disordered garnet material, a sensitizer ion, and at least one rare earth emitter ion.
2. The wavelength converting structure of claim 1 , wherein the structurally disordered garnet material comprises a cubic garnet host lattice with 8-fold coordinated Gd atoms, 6-fold coordinated Ga atoms, and 4-fold coordinated Ga atoms.
3. The wavelength converting structure of claim 1 , wherein the structurally disordered garnet material comprises one or more atoms selected from the group Sc, Lu, Ga and Al that can occupy more than one lattice site and at a concentration greater than 1 atom %.
4. The wavelength converting structure of claim 1 , wherein the rare earth emitter ion comprises at least one of Tm, Ho, La, Y, Yb, Nd, Er, and Ce.
5. The wavelength converting structure of claim 1 , wherein the rare earth emitter ion consists of Tm and Ho.
6. The wavelength converting structure of claim 1 , wherein the rare earth emitter ion consists of Tm.
7. The wavelength converting structure of claim 1 , wherein the SWIR phosphor comprises (Gd 3−u−v−x−y−z Lu x Tm y Ho z Sc v RE u )[Sc 2−a−b Lu a Cr b Ga d Al e ]{Ga 3−c Al c }O 12 with RE=La, Y, Yb, Nd, Er, Ce and 0≤u≤2, 0<v≤1, 0<x≤1, 0<y≤0.5, 0≤z≤0.05, 0<a≤1, 0<b≤0.3, 0≤c≤3, 0<d≤1.8, 0≤e≤1.8.
8. The wavelength converting structure of claim 6 , wherein the SWIR phosphor comprises at least one of Gd 2.367 Ho 0.01 Tm 0.152 Sc 1.6 Lu 0.27 Ga 1.8 Al 1.78 Cr 0.04 O 12 , Gd 2.59 Tm 0.24 Ho 0.02 Sc 0.75 Lu 0.3 Ga 2 Al 2 Cr 0.1 O 12 , Gd 2 Ho 0.013 Tm 0.2 Sc 0.67 Lu 0.24 Ga 1.6 Al 3.2 Cr 0.08 O 12 , and Gd 2.67 Ho 0.01 Tm 0.17 Sc 1.8 Lu 0.3 Ga 2 AlCr 0.05 O 12 .
9. The wavelength converting structure of claim 1 , further comprising an additional IR phosphor having emission in the wavelength range of 1100-1700 nm.
10. The wavelength converting structure of claim 9 , wherein the additional IR phosphor comprises one or more of Ni2+, or Ni2+ and Cr3+ doped spinel, perovskite, and garnet type IR phosphor emitting in the 1000-1700 nm range.
11. A luminescent material that emits lighting having emissions wavelengths in the range of 1600-2200 nm, the luminescent material comprising a structurally disordered garnet material doped with at least one sensitizer ion and at least one rare earth emitter ion.
12. The luminescent material of claim 11 , wherein the structurally disordered garnet material comprises a cubic garnet host lattice with 8-fold coordinated Gd atoms, 6-fold coordinated Ga atoms, and 4-fold coordinated Ga atoms.
13. The luminescent material of claim 11 , wherein the structurally disordered garnet material comprises one or more atoms selected from the group Sc, Lu, Ga and Al that can occupy more than one lattice site and at a concentration greater than 1 atom %.
14. The luminescent material of claim 11 , wherein the rare earth emitter ion comprises at least one of Tm, Ho, La, Y, Yb, Nd, Er, and Ce.
15. The luminescent material of claim 11 , wherein the rare earth emitter ion consists of Tm and Ho.
16. The luminescent material of claim 11 , comprising (Gd 3−u−v−x−y−z Lu x Tm y Ho z Sc v RE u )[Sc 2−a−b Lu a Cr b Ga d Al e ]{Ga 3−c Al c }O 12 with RE=La, Y, Yb, Nd, Er, Ce and 0≤u≤2, 0<v≤1, 0<x≤1, 0<y≤0.5, 0≤z≤0.05, 0<a≤1, 0<b≤0.3, 0≤c≤3, 0<d≤1.8, 0≤e≤1.8.
17. The luminescent material of claim 11 , wherein the rare earth emitter ion consists of Tm.
18. The luminescent material of claim 11 , wherein the SWIR phosphor comprises at least one of Gd 2.367 Ho 0.01 Tm 0.152 Sc 1.6 Lu 0.27 Ga 1.8 Al 1.78 Cr 0.04 O 12 , Gd 2.59 Tm 0.24 Ho 0.02 Sc 0.75 Lu 0.3 Ga 2 Al 2 Cr 0.1 O 12 , Gd 2 Ho 0.013 Tm 0.2 Sc 0.67 Lu 0.24 Ga 1.6 Al 3.2 Cr 0.08 O 12 , and Gd 2.67 Ho 0.01 Tm 0.17 Sc 1.8 Lu 0.3 Ga 2 AlCr 0.05 O 12 .
19. An IR emitting device comprising:
a wavelength converting structure, the wavelength converting structure comprising an SWIR phosphor having emission over a wavelength range of 1600-2200 nm with a continuous emission spectrum over a spectral width of at least 500 nm; and
a light source configured to emit into the wavelength converting structure.
20. The IR emitting device of claim 19 , wherein the SWIR phosphor comprises (Gd 3−u−v−x−y−z Lu x Tm y Ho z Sc v RE u )[Sc 2−a−b Lu a Cr b Ga d Al e ]{Ga 3−c Al c }O 12 with RE=La, Y, Yb, Nd, Er, Ce and 0≤u≤2, 0<v≤1, 0<x≤1, 0<y≤0.5, 0≤z≤0.05, 0<a≤1, 0<b≤0.3, 0≤c≤3, 0<d≤1.8, 0≤e≤1.8.