Yellow-green epitaxial transparent substrate-LEDs and lasers based on a strained-InGaP quantum well grown on an indirect bandgap substrate

1. A light-emitter structure comprising:

a platform;

an In x (Al y Ga 1-y ) 1-x P lower clad region formed on said platform and having a lattice constant between approximately 5.49 Å and 5.62 Å;

a strained quantum well active region formed on said lower clad region; and

an In x (Al y Ga 1-y ) 1-x P upper clad region formed on said strained quantum well active region.

2. The light-emitter structure of claim 1 , wherein said strained quantum well active region comprises an In x (Al y Ga 1-y ) 1-x P strained quantum-well active region where 0.27≦x≦0.50 and 0≦y≦1 formed on said lower clad region.

3. The light-emitter structure of claim 1 , wherein said upper clad region is approximately lattice-matched to said lower clad region formed on said strained quantum well.

4. The light-emitter structure of claim 1 , wherein said platform comprises a ∇ x [In x (Al y Ga 1-y ) 1-x P] graded buffer placed between a substrate and said lower clad region.

5. The light-emitter structure of claim 4 , wherein said substrate comprises GaP.

6. The light-emitter structure of claim 1 further comprising a cap layer that is deposited on said upper clad region.

7. The light-emitter structure of claim 6 , wherein said cap layer comprises InGaP that is deposited on and approximately lattice-matched to said upper clad region.

8. The light-emitter structure of claim 1 further comprising separate confinement heterostructures (SCH) placed between said upper clad region, said lower clad region and said strained quantum well active region.

9. The light-emitter structure of claim 8 , wherein said separate confinement heterostructures (SCH) comprises InGaP or InAlGaP that is approximately lattice-matched to said clad layer, and placed between said upper clad region, lower clad region and said strained quantum well active region.

10. The light-emitter structure of claim 1 , wherein said upper and lower clad regions comprise concentration values x=0.22 and y=0.2.

11. The light-emitter structure of claim 1 , wherein said strained quantum well active region comprises concentration values x=0.32 and y=0.

12. The light-emitter structure of claim 1 , wherein said lower clad region and upper clad region are n-doped and p-doped, respectively.

13. The light-emitter structure of claim 1 , wherein said lower clad region and upper clad region are p-doped and n-doped, respectively.

14. The light-emitter structure of claim 4 , wherein said ∇ x [In x (Al y Ga 1-y ) 1-x P] graded buffer and said lower clad region are n-doped, and said upper clad is p-doped.

15. The light-emitter structure of claim 4 , wherein said ∇ x [In x (Al y Ga 1-y ) 1-x P] graded buffer and said lower clad region are p-doped, and said upper clad is n-doped.

16. The light-emitter structure of claim 4 , wherein said ∇ x [In x (Al y Ga 1-y ) 1-x P] graded buffer is undoped, said lower clad region is n-doped, and said upper clad region is p-doped.

17. The light-emitter structure of claim 4 , wherein said ∇ x [In x (Al y Ga 1-y ) 1-x P] graded buffer is undoped, said lower clad region is p-doped, and said upper clad region is n-doped.

18. The light-emitter structure of claim 1 , wherein said strained quantum well active region is doped.

19. The light-emitter structure of claim 8 , wherein said SCH structures are doped.

20. The light-emitter structure of claim 1 further comprising a double top contact.

21. The light-emitter structure of claim 1 further comprising an insulator stripe top contact.

22. The light-emitter structure of claim 1 , wherein said platform comprises a substrate that is lattice-matched to said lower clad region.