Thin-film, flexible optoelectronic devices incorporating a single lattice-matched dilute nitride junction and methods of fabrication

1. A method for fabricating a single-junction solar cell, comprising:

providing a substrate;

forming a release layer on the substrate;

epitaxially growing a dilute nitride single p-n structure on the release layer, the dilute nitride single p-n structure having a lattice constant that matches a lattice constant of the substrate, the dilute nitride single p-n structure including a single-crystalline semiconductor material, wherein the dilute nitride single p-n structure forms the single-junction solar cell; and

separating the single-junction solar cell from the substrate by removing the release layer.

2. The method of claim 1 , wherein separating the single-junction solar cell from the substrate includes orienting the single-junction solar cell such that the dilute nitride single p-n structure is nearest to a surface of the single junction solar cell upon which light is to be incident.

3. The method of claim 1 , further comprising forming, as part of backside processing, additional layers on a surface of the single-junction solar cell, wherein the additional layers include a reflector and one or more layers between the reflector and the dilute nitride single p-n structure.

4. The method of claim 1 , further comprising providing, for the single-junction solar cell, a support layer having one or more of a dielectric layer, a semiconductor contact layer, a passivation layer, a transparent conductive oxide layer, an anti-reflective coating, an adhesive layer, an epoxy layer, or a plastic coating, wherein the support layer is deposited on the dilute nitride single p-n structure before the single-junction solar cell is separated from the substrate.

5. The method of claim 1 , wherein the substrate includes one of GaAs or Ge.

6. The method of claim 1 , wherein the dilute nitride single p-n structure includes one or more of GaInNAs, GaInNAsSb, alloys thereof, or derivatives thereof.

7. The method of claim 1 , wherein:

the dilute nitride single p-n structure includes Ga 1-y In y As 1-x-z N x Sb z ,

a concentration y of In is in the range of 0-20%,

a concentration x of N is in the range of 0-6%, and

a concentration z of Sb is in the range of 0-8%.

8. The method of claim 1 , wherein the lattice constant of the dilute nitride single p-n structure matches the lattice constant of the substrate with a mismatch or strain of <0.4%.

9. The method of claim 1 , wherein an epitaxial growth process for forming the dilute nitride single p-n structure is a molecular beam epitaxy (MBE) process.

10. The method of claim 1 , wherein an epitaxial growth process for forming the dilute nitride single p-n structure includes one or more of:

a metalorganic chemical vapor deposition (MOCVD) process,

a hydride vapor phase epitaxy (HVPE) process,

a molecular beam epitaxy (MBE) process,

a metalorganic vapor phase epitaxy (MOVPE or OMVPE) process,

a liquid phase epitaxy (LPE) process,

a close-space vapor transport (CSVT) epitaxy process,

a plasma enhanced chemical vapor deposition (PECVD) process,

a physical vapor deposition (PVD) process,

an atmospheric pressure chemical vapor deposition (APCVD) process,

an atomic layer deposition (ALD) process,

a low pressure chemical vapor deposition (LPCVD) process,

a hot-wire chemical vapor deposition (HWCVD) process,

an inductively coupled plasma enhanced chemical vapor deposition (ICP-CVD) process, or

other forms of CVD.

11. The method of claim 1 , wherein an epitaxial growth process for forming the dilute nitride single p-n structure includes a combination of MBE and MOCVD.

12. The method of claim 1 , wherein separating the single-junction solar cell from the substrate includes performing an epitaxial liftoff (ELO) process for lifting the single-junction solar cell off the substrate.

13. The method of claim 1 , wherein the release layer includes AlAs.

14. The method of claim 1 , wherein the release layer includes AlGaAs having a concentration of Al x Ga 1-x As, where x=1 to 0.3.

15. The method of claim 1 , wherein the release layer includes AlGaInP having a concentration of (Al x Ga 1-x ) 0.5 In 0.5 P, where x=1 to 0.

16. The method of claim 1 , wherein:

the substrate includes GaAs or Ge, and

the dilute nitride single p-n structure has a bandgap of approximately 1.1 eV-1.35 eV.

17. The method of claim 1 , wherein:

the substrate includes GaAs or Ge, and

the dilute nitride single p-n structure has a bandgap of approximately 1.3 eV-1.4 eV.

18. The method of claim 1 , wherein:

the substrate includes GaAs or Ge, and

the dilute nitride single p-n structure has a bandgap of approximately 1.34 eV.

19. The method of claim 1 , wherein:

the substrate includes GaAs or Ge, and

the dilute nitride single p-n structure has a bandgap of approximately 0.9 eV-1.4 eV.

20. The method of claim 1 , further comprising:

forming a reflector on the dilute nitride single p-n structure, and

separating the single-junction solar cell from the substrate includes separating the dilute nitride single p-n structure and the reflector from the substrate.

21. The method of claim 1 , wherein the dilute nitride single p-n structure includes a p-n junction, a position of the p-n junction within the dilute nitride single p-n structure being near a front side of the single-junction solar cell.

22. The method of claim 1 , wherein the dilute nitride single p-n structure is a heterojunction.

23. The method of claim 1 , wherein the dilute nitride single p-n structure includes a p-n junction, a position of the p-n junction within the dilute nitride single p-n structure being away from a incident side of a light of the single-junction solar cell.

24. The method of claim 1 , wherein the dilute nitride single p-n structure is a homojunction.