Light emitting device and the use thereof

1. A light emitting device, comprising:

a die including a first semiconductor light-emitting layer emitting a first color light having a first wavelength range, and a second semiconductor light-emitting layer emitting a second color light having a second wavelength range different from the first wavelength range; and

a photostimulable luminescent substance excitable by at least one of the first and second color lights to emit a third color light having a third wavelength range, the third color light being mixed with the first and second color lights to emit a light blend having a wavelength range covering the first, second, and third wavelength ranges,

wherein said die further includes a p-type cladding layer and an n-type cladding layer, said first and second semiconductor light-emitting layers being disposed between said p-type and n-type cladding layers, said first semiconductor light-emitting layer being proximate to said p-type cladding layer, and including a first barrier film proximate to said p-type cladding layer, a second barrier film, and a carrier confining film between said first and second barrier films and having a plurality of alternating peaks and valleys, said carrier confining film having an energy gap smaller than those of said first and second barrier films.

2. The light emitting device as claimed in claim 1 , wherein the light blend produces white light.

3. The light emitting device as claimed in claim 1 , wherein said carrier confining film is made of a material having a formula Al (1-x-y) In y Ga x N, wherein 0≦x<1, 0<y≦1, and 0≦1-x-y<1.

4. The light emitting device as claimed in claim 1 , wherein said first semiconductor light-emitting layer has a valley density ranging from 5% to 75%, the valley density being defined by a ratio of a summation of the widths of said valleys to a total length of said first semiconductor light-emitting layer along a direction that the widths are measured.

5. The light emitting device as claimed in claim 1 , wherein said die further includes a third semiconductor light-emitting layer emitting a UV light.

6. The light emitting device as claimed in claim 1 , wherein said third semiconductor light-emitting layer is proximate to said p-type cladding layer, said second semiconductor light-emitting layer being proximate to said n-type cladding layer, said first semiconductor light-emitting layer being disposed between said second and third semiconductor light-emitting layers.

7. The light emitting device as claimed in claim 1 , wherein the first wavelength range is from 440 nm to 480 nm.

8. The light emitting device as claimed in claim 1 , wherein the second wavelength range is from 520 nm to 560 nm.

9. The light emitting device as claimed in claim 1 , wherein the third wavelength range is from 575 nm to 650 nm.

10. The light emitting device as claimed in claim 5 , wherein the UV light has a wavelength smaller than 440 nm.

11. The light emitting device as claimed in claim 1 , wherein said photostimulable luminescent substance includes a material selected from the group consisting of LiEuW 2 O 8 , (Y,La) 2 O 3 :Eu, (Ba,Mg,Zn)S:Eu, Y 2 O 2 S:Eu, Y 2 O 2 S:Bi, YVO 4 :Eu, YVO 4 :Bi, SrY 2 S 4 :Eu, CaLaS 4 :Ce, (Ba,Ca,Sr)S:Eu, SrS:Eu, (Zn,Cd)S:Ag, (Zn,Cd)S:Cl, AEu x Ln 1-x M 2 O 8 ,Y 2 O 3 :Eu, Y 2 O 3 :Bi, QP 2 O 7 :Eu, QP 2 O 7 :Mn, and 3.5MgO.0.5MgF 2 .GeO 2 :Mn, wherein:

0<x≦1;

A is Li, Na, K, Rb, or Cs;

Ln is Y, La, Gd, or Lu;

P is W or Mo; and

Q is Sr, Ca, Ba, or Mg.

12. The light emitting device as claimed in claim 1 , further comprising a holding member holding said die and said photostimulable luminescent substance.

13. The light emitting device as claimed in claim 12 , wherein said holding member includes a light-transmissive encapsulating body to encapsulate said die, a first lead electrically connected to said die, and a second lead electrically connected to said die, said photostimulable luminescent substance being contained in said light-transmissive encapsulating body.

14. The light emitting device as claimed in claim 12 , wherein said holding member includes a first lead electrically connected to said die, and a second lead electrically connected to said die and having a receiving recess, said die being received in said receiving recess, said photostimulable luminescent substance being filled in said receiving recess to encapsulate said die.