METHOD FOR MANUFACTURING A SOLAR CELL WITH A SURFACE-PASSIVATING DIELECTRIC DOUBLE LAYER, AND CORRESPONDING SOLAR CELL

• US 20100263725A1
• Filed: 11/06/2008
• Published: 10/21/2010
• Est. Priority Date: 11/14/2007
• Status: Active Grant

• Current Assignee: Hanwha Solutions Corporation (Hanwha Corporation)
• Original Assignee: Institut Fur Solarenergieforschung GmbH (State of Lower Saxony)
• Inventors: Schmidt, Jan
• Granted Patent: US 9,893,215 B2
• Time in Patent Office: Days
• US Class Current: 136/261
• CPC Class Codes: C23C 16/403 of aluminium, magnesium or beryllium
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• CPC Class Codes: H01L 31/02168 the coatings being antireflective or having enhancing optical properties for the solar cells
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells

Abstract

A solar cell with a dielectric double layer and also a method for the manufacture thereof are described. A first dielectric layer (3), which contains aluminium oxide or consists of aluminium oxide, and a second, hydrogen-containing dielectric layer (5) are produced by means of atomic layer deposition, allowing very good passivation of the surface of solar cells to be achieved.

Claims

1. Method for manufacturing a silicon solar cell, including the following steps:

providing a silicon substrate (1);

depositing a first dielectric layer (3) on a surface of the silicon substrate by means of atomic layer deposition, wherein the first dielectric layer comprises aluminium oxide; and

depositing a second dielectric layer (5) on a surface of the first dielectric layer (3), the materials of the first and the second dielectric layer differing and hydrogen being embedded into the second dielectric layer.

2. Method according to claim 1, wherein, for depositing the first dielectric layer, the silicon substrate is firstly flushed with an aluminium-containing compound comprising at least one of the components Al(CH₃)₃, A1Cl₃, Al(CH₃)₂Cl and (CH₃)₂(C₂H₅)N:

AlH₃, so that an aluminium-containing layer is deposited on the surface of the silicon substrate, and wherein the aluminium-containing layer is subsequently oxidised to higher valency in an oxygen-containing atmosphere.

3. Method according to claim 1, wherein the second dielectric layer comprises a material selected from the group comprising silicon nitride, silicon oxide and silicon carbide.

4. Method according to claim 1, wherein the second dielectric layer is manufactured by means of a PECVD method.

5. Method according to claim 1, wherein the second dielectric layer is deposited in such a way that it has a hydrogen content of at least 1 at.

6. Method according to claim 1, wherein a high-temperature step is carried out at temperatures above 600°

C., preferably above 700°

C. and more preferably above 800°

C., after the depositing of the second dielectric layer.

7. Method according to claim 1, wherein the first dielectric layer is deposited at a thickness of less than 50 nm, preferably less than 30 nm and more preferably less than 10 nm.

8. Method according to claim 1, wherein the second dielectric layer is deposited at a thickness of more than 50 nm, preferably more than 100 nm and more preferably more than 150 nm.

14. Solar cell manufactured using a method according to claim 1.

15. Method according to claim 2, wherein the second dielectric layer comprises a material selected from the group comprising silicon nitride, silicon oxide and silicon carbide.

16. Method according to claim 2, wherein the second dielectric layer is manufactured by means of a PECVD method.

17. Method according to claim 3, wherein the second dielectric layer is manufactured by means of a PECVD method.

18. Method according to claim 2, wherein the second dielectric layer is deposited in such a way that it has a hydrogen content of at least 1 at. %, preferably at least 2 at. % and more preferably at least 5 at. %.

19. Method according to claim 3, wherein the second dielectric layer is deposited in such a way that it has a hydrogen content of at least 1 at. %, preferably at least 2 at. % and more preferably at least 5 at. %.

9. Solar cell comprising:

a silicon substrate (1);

a first dielectric layer (3) comprising aluminium oxide on a surface of the silicon substrate (1);

a second dielectric layer (5) on a surface of the first dielectric layer (3), the materials of the first and the second dielectric layer differing and hydrogen being embedded into the second dielectric layer.

10. Solar cell according to claim 9, wherein the first dielectric layer is deposited by means of atomic layer deposition, so that it is substantially atomically tight.

11. Solar cell according to claim 9, wherein the second dielectric layer comprises a material selected from the group comprising silicon nitride, silicon oxide and silicon carbide.

12. Solar cell according to claim 9, wherein the first dielectric layer has a thickness of less than 50 nm, preferably less than 30 nm and more preferably less than 10 nm.

13. Solar cell according to claim 9, wherein the second dielectric layer has a thickness of more than 50 nm, preferably more than 100 nm and more preferably more than 150 nm.

20. Solar cell according to claim 10, wherein the second dielectric layer comprises a material selected from the group comprising silicon nitride, silicon oxide and silicon carbide.