Solar cell and manufacturing method thereof

• US 20070290283A1
• Filed: 12/28/2006
• Published: 12/20/2007
• Est. Priority Date: 12/29/2005
• Status: Active Grant

• Current Assignee: Intellectual Keystone Technology LLC
• Original Assignee: Samsung SDI Company Limited
• Inventors: Park, Sang-Wook, Cho, Eun-Chel, Kim, Dae-won
• Granted Patent: US 7,884,375 B2
• Time in Patent Office: Days
• US Class Current: 257/431
• CPC Class Codes: H01L 31/022425 for solar cells
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A solar cell and a manufacturing method thereof. A method of manufacturing a solar cell includes: forming an emitter layer on a first surface of a semiconductor substrate; forming an insulation layer on the emitter layer; applying a chemical compound including a dopant having a conductive type of the emitter layer on the insulation layer according to a pattern; forming a high concentration emitter portion by removing a portion of the insulation layer corresponding to a positioning of the chemical compound and diffusing the dopant toward the emitting layer; removing the chemical compound; and forming a first electrode electrically connected to the high concentration emitter portion.

Claims

1. A method of manufacturing a solar cell, the method comprising:

forming an emitter layer on a first surface of a semiconductor substrate;

forming an insulation layer on the emitter layer;

applying a chemical compound comprising a dopant having a conductive type of the emitter layer on the insulation layer according to a pattern;

forming a high concentration emitter portion by;

removing a portion of the insulation layer corresponding to a positioning of the chemical compound; and

diffusing the dopant towards the emitter layer;

removing the chemical compound; and

forming a first electrode electrically connected to the high concentration emitter portion.

2. The method of claim 1, wherein the dopant comprises phosphorus (P).

3. The method of claim 1, wherein the chemical compound further comprises phosphorus pentoxide (P₂O₅) and/or phosphorus chloride oxide (POCl₃).

4. The method of claim 1, wherein the chemical compound is applied by using a process selected from the group consisting of screen printing, dispensing, electroless-plating, electroplating, and combinations thereof.

5. The method of claim 1, wherein the chemical compound is applied by using a screen printing process.

6. The method of claim 1, wherein the high concentration emitter portion is formed by performing a thermal annealing process for diffusing the dopant.

7. The method of claim 6, wherein the thermal annealing process is performed at a temperature in a range from about 850°

C. to about 950°

C.

8. The method of claim 6, wherein the performing the thermal annealing process comprises using a heat source comprising an infrared lamp and/or a furnace.

9. The method of claim 1, wherein the pattern of the chemical compound corresponds to a pattern by which the first electrode is formed.

10. The method of claim 1, further comprising forming a second electrode on a second surface of the semiconductor substrate, the second electrode being electrically connected to the semiconductor substrate.

11. The method of claim 10, wherein the forming the second electrode comprises screen printing an aluminum paste on the second surface of the semiconductor substrate.

12. The method of claim 10, wherein the forming the second electrode further comprises forming a rear electric field layer located between the second electrode and the semiconductor substrate.

13. The method of claim 1, wherein the emitter layer is formed by using a process selected from the group consisting of high-temperature diffusion, spraying, screen printing, ion showering, and combinations thereof.

14. The method of claim 1, wherein the insulation layer comprises silicon nitride, silicon oxide, and/or titanium oxide.

15. The method of claim 1, wherein the insulation layer is formed by using a process selected from the group consisting of plasma enhanced chemical vapor deposition, electron beam deposition, screen printing, spraying, and combinations thereof.

16. The method of claim 1, wherein the applying the chemical compound comprises screen printing the chemical compound on the insulation layer.

17. The method of claim 1, wherein the first electrode contacts the insulation layer at a substantially uneven surface of the insulation layer.

18. A solar cell comprising:

a semiconductor substrate;

an emitter layer disposed on the semiconductor substrate;

a first electrode disposed on the emitter layer and electrically connected to the emitter layer; and

an insulation layer disposed on one or more regions of the emitter layer where the first electrode is not disposed,

wherein the emitter layer comprises a high concentration emitter portion corresponding to a positioning of the first electrode, and

wherein the insulation layer comprises a substantially uneven surface in contact with the first electrode.

19. The solar cell of claim 18, wherein the high concentration emitter portion is formed by:

applying a chemical compound to an insulation layer portion, the chemical compound comprising a dopant;

performing thermal annealing to eliminate the insulation layer portion, thereby exposing a portion of the emitter layer, using the chemical compound; and

diffusing the dopant towards the exposed portion of the emitter layer.