PHOTOVOLTAIC DEVICE WITH A DISCONTINUOUS INTERDIGITATED HETEROJUNCTION STRUCTURE

• US 20100032014A1
• Filed: 03/26/2008
• Published: 02/11/2010
• Est. Priority Date: 03/28/2007
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Bettinelli, Armand, Desrues, Thibaut
• Granted Patent: US 8,723,023 B2
• Time in Patent Office: Days
• US Class Current: 136/258
• CPC Class Codes: H01L 31/022441 Electrode arrangements specially adapted for back-contact solar cells
• CPC Class Codes: H01L 31/0747 comprising a heterojunction of crystalline and amorphous materials, e.g. heterojunction with intrinsic thin layer
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A photovoltaic device which includes: a) a substrate based on a crystalline semi-conductor material; b) a first electrode which includes at least one heterojunction made on one face, referred to as the rear face, of the substrate, where this heterojunction includes a layer based on a doped amorphous semi-conductor material; and c) a second electrode. The first and second electrodes are arranged on the rear face of the substrate according to an interdigitated combs design, and where the layer includes multiple portions of the doped amorphous semi-conductor material which are unconnected and spaced apart from each other.

Claims

1. A photovoltaic device which includes:

a substrate based on a crystalline semi-conductor material,

a first electrode which includes at least one heterojunction made on one face, referred to as the rear face, of the substrate, where this heterojunction includes a layer based on a doped amorphous semi-conductor material,

a second electrode,

where the first and second electrodes are arranged on the rear face of the substrate according to an interdigitated combs design, where the layer includes multiple portions of the doped amorphous semi-conductor material which are unconnected and spaced apart from each other, each finger of the combs comprising several unconnected portions of amorphous semi-conductor material.

2. The device according to claim 1, where the first electrode forms an emitter of the photovoltaic device.

3. The device according to claim 1, which in addition includes at least one intrinsic amorphous semi-conductor based layer arranged between the substrate and the doped amorphous semi-conductor layer.

4. The device according to claim 3, where the second electrode includes at least one metallization made on the intrinsic amorphous semi-conductor based layer.

5. The device according to claim 1, where the portions of doped amorphous semi-conductor material are approximately rectangular in shape.

6. The device according to claim 1, where the first electrode layer, referred to as the first layer, is based on an amorphous semi-conductor material doped with a first type of conductivity, and where the second electrode includes at least one heterojunction which includes a second layer based on an amorphous semi-conductor material doped with a second type of conductivity.

7. The device according to claim 6, which in addition includes at least one intrinsic amorphous semi-conductor based layer arranged between the substrate and the first and second doped amorphous semi-conductor layers.

8. The device according to claim 6, where the second layer includes multiple portions of the semi-conductor material doped with the second type of conductivity which are distinct and spaced apart from each other.

9. The device according to claim 8, where the portions of doped amorphous semi-conductor material are approximately rectangular in shape.

10. The device according to claim 9, where the length and width dimensions of the portions of semi-conductor material doped with the first type of conductivity are different to those of the portions of semi-conductor material doped with the second type of conductivity.

11. The device according to claim 1, where the portions of amorphous semi-conductor material doped with a given type of conductivity are insulated from each other by portions of insulating material arranged at least between said portions of doped amorphous semi-conductor material.

12. The device according to claim 11, where the portions of insulating material are also partially arranged on the portions of doped amorphous semi-conductor material.

13. The device according to claim 1, where the portions of amorphous semi-conductor material doped with a given type of conductivity are electrically connected together by metallizations made on said portions of doped amorphous semi-conductor material.

14. The device according to claim 13, where the metallizations made on the portions of amorphous semi-conductor materials doped with a given type of conductivity are formed by a continuous portions based on a conductive material.

15. The device according to claim 13, where the metallizations made on the portions of amorphous semi-conductor materials doped with a given type of conductivity include portions of a conductive material which are distinct and spaced apart from each other.

16. The device according to claim 13, which in addition includes at least one layer based on at least one conductive material arranged between the portions of doped amorphous semi-conductor material and the metallizations.

17. The device according to claim 16, where said conductive material of the layer is a conductive transparent oxide such as ITO and/or a metal.

18. The device according to claim 16, where the conductive layer includes portions of the conductive material which are distinct and spaced apart from each other, are of a shape approximately similar to that of the portions of doped amorphous semi-conductor material and are approximately arranged at the location of the portions of doped amorphous semi-conductor material.

19. The device according to claim 1, where said device is a photovoltaic cell with heterojunctions and rear-face contacts.

20. A method of producing a photovoltaic device which includes at least steps for:

realization of a first electrode which includes at least one step for deposition, onto a face referred to as the rear face of a crystalline semi-conductor material based substrate, of a doped amorphous semi-conductor material based layer, through a mask whose design includes discontinuous openings, forming multiple portions of the doped amorphous semi-conductor material which are distinct and spaced apart from each other,

realization of a second electrode,

where the first and second electrodes are arranged on the rear face of the substrate according to an interdigitated combs design such that each finger of the combs comprises several unconnected portions of amorphous semi-conductor material.

21. The method according to claim 20, which in addition includes, before the realization of the first electrode, a step for the deposition of an intrinsic amorphous semi-conductor material based layer on the rear face of the substrate, where the doped amorphous semi conductor material based layer is deposited on the intrinsic amorphous semi-conductor layer, the realization of the second electrode including a step for the deposition of at least one metallization on the intrinsic amorphous semi-conductor layer.

22. The method according to claim 20, where the layer, referred to as the first layer, is based on an amorphous semi-conductor material doped with a first type of conductivity, where the realization of the second electrode includes a step for the deposition of a second layer based on an amorphous semi-conductor material doped with a second type of conductivity, on the rear face of the substrate.

23. The method according to claim 22, which in addition includes, before the realization of the first electrode, a step for the deposition of an intrinsic amorphous semi-conductor based layer on the rear face of the substrate.

24. The method according to claim 23 where the deposition of the second layer based on an amorphous semi-conductor material doped with a second type of conductivity is achieved through the deposition of the amorphous semi-conductor material doped with a second type of conductivity through a second mask whose design includes discontinuous openings, forming several portions of the amorphous semi-conductor material doped with the second type of conductivity which are distinct and spaced apart from each other.

25. The method according to claim 20, which includes in addition, once the first and/or second electrode has been made, a step for the deposition of an insulation material at least between the portions of amorphous semi-conductor material doped with a given type of conductivity through a mask whose design includes discontinuous openings.

26. The method according to claim 20, which includes in addition, before the first electrode has been made, a step for the deposition of an insulating material through a mask whose design includes discontinuous openings, intended to form portions of insulating material at least between said portions of amorphous semi-conductor material doped with a given type of conductivity.

27. The method according to claim 25, where the step for the deposition of the insulating material between said portions of amorphous semi-conductor materials doped with a given type of conductivity also carries out the deposition of the insulating material partially on the portions of doped semi-conductor material.

28. The method according to claim 20, which includes in addition, once the first and/or second electrode have been made, a step for the deposition, through a mask whose design includes discontinuous openings, of portions of at least one conductive material onto the portions of amorphous semi-conductor material doped with a given type of conductivity.

29. The method according to claim 28, where the portions of conductive material are deposited on the portions of doped amorphous semi-conductor material through the mask used for the deposition of the layer of doped amorphous semi-conductor material for the first electrode, and when the second electrode includes a second layer of amorphous semi-conductor material doped with the second type of conductivity, deposited through the second mask, the portions of conductive material are deposited on the portions of amorphous semi-conductor material doped with the second type of conductivity through the second mask.

30. The method according to claim 20, which in addition includes a step for the realization of metallizations on the portions of doped amorphous semi-conductor, electrically connecting together the portions of amorphous semi-conductor material doped with a given type of conductivity.

31. The method according to claim 30 where the realization of metallizations is achieved through the deposition of a conductive material through a mask which includes discontinuous openings, forming portions of conductive material which are distinct and spaced apart from each other.