SOLAR CELL AND METHOD OF MANUFACTURING THE SAME

• US 20090120494A1
• Filed: 02/22/2008
• Published: 05/14/2009
• Est. Priority Date: 07/13/2007
• Status: Abandoned Application

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Moon, In-Sik, Kim, Dae-Won
• Application Number:
  US12/036,118
• Publication Number:
  US 20090120494A1
• Time in Patent Office: Days
• US Class Current: 136/256
• CPC Class Codes: H01L 31/022466 made of transparent conductive layers, e.g. TCO, ITO layers
• CPC Class Codes: H01L 31/1884 Manufacture of transparent electrodes, e.g. TCO, ITO
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A solar cell having a high photoelectric efficiency by minimizing (or reducing) electron transfer resistance and electrode shading loss. The solar cell includes a semiconductor substrate; an emitter layer on a first side of the semiconductor substrate; a conductive transparent electrode layer on the emitter layer; a first electrode on the conductive transparent electrode layer and electrically connected to the conductive transparent electrode layer; and a second electrode on a second side of the semiconductor substrate and electrically connected to the semiconductor substrate. The conductive transparent electrode layer has a specific resistance of about 500 μΩ·cm or less. The emitter layer may be doped with a low concentration of impurities resulting in improve optical response at a short wavelength and minimization (or reduction) of recombination loss.

Claims

1. A solar cell comprising:

a semiconductor substrate;

an emitter layer on a first side of the semiconductor substrate;

a conductive transparent electrode layer on the emitter layer;

a first electrode on the conductive transparent electrode layer and electrically connected to the conductive transparent electrode layer; and

a second electrode on a second side of the semiconductor substrate and electrically connected to the semiconductor substrate,

wherein the conductive transparent electrode layer has a specific resistance of about 500 μ

Ω

·

cm or less.

2. The solar cell of claim 1, wherein the specific resistance of the conductive transparent electrode layer is lower than that of the emitter layer.

3. The solar cell of claim 1, wherein the conductive transparent electrode layer has a transmission rate of about 90% or more for a wavelength ranging from about 350 to about 800 nm.

4. The solar cell of claim 1, wherein the conductive transparent electrode layer has a refractive index ranging from about 1.7 to about 2.5.

5. The solar cell of claim 1, wherein the conductive transparent electrode layer has a thickness ranging from about 60 to about 100 nm.

6. The solar cell of claim 1, wherein the conductive transparent electrode layer comprises a material selected from the group consisting of indium tin oxide (ITO), tin oxide, AgO, ZnO—

(Ga₂O₃ or Al₂O₃), fluorine tin oxide (FTO), and mixtures thereof.

7. The solar cell of claim 1, wherein the first electrode comprises a plurality of first electrodes spaced apart by an interval ranging from about 2.5 to about 8 mm from each other.

8. The solar cell of claim 1, wherein the first electrode comprises a material selected from the group consisting of Al, Ag, Ni, Cu, Ti, Pd, Cr, W, a conductive polymer, and combinations thereof.

9. The solar cell of claim 1, wherein the second electrode comprises a material selected from the group consisting of Al, Ag, Ni, Cu, Ti, Pd, Cr, W, a conductive polymer, and combinations thereof.

10. The solar cell of claim 1, wherein the semiconductor substrate is a p-type silicon substrate.

11. The solar cell of claim 1, wherein the semiconductor substrate has a specific resistance ranging from about 0.5 to about 3 Ω

·

cm.

12. The solar cell of claim 1, wherein the emitter layer is an n-type silicon substrate.

13. The solar cell of claim 1, wherein the emitter layer has a surface resistance of about 500% or more.

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

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

forming a conductive transparent electrode layer on the emitter layer;

forming a first electrode electrically connected to the conductive transparent electrode layer on the conductive transparent electrode layer; and

forming a second electrode on a second side of the semiconductor substrate.

15. The method of claim 14, wherein the semiconductor substrate is a p-type silicon substrate.

16. The method of claim 14, wherein the semiconductor substrate has a specific resistance ranging from about 0.5 to about 3 Ω

·

cm.

17. The method of claim 14, wherein the emitter layer is an n-type silicon substrate.

18. The method of claim 14, wherein the emitter layer has a surface resistance of about 50Ω

/□

) or more.

19. The method of claim 14, wherein the specific resistance of the conductive transparent electrode layer is lower than that of the emitter layer.

20. The method of claim 14, wherein the conductive transparent electrode layer has a specific resistance of about 500 μ

Ω

·

cm or less.

21. The method of claim 14, wherein the conductive transparent electrode layer has a transmission rate of about 90% or more for a wavelength ranging from about 350 to about 800 nm.

22. The method of claim 14, wherein the conductive transparent electrode layer has a refractive index ranging from about 1.7 to about 2.5.

23. The method of claim 14, wherein the conductive transparent electrode layer has a thickness ranging from about 60 to about 100 nm.

24. The method of claim 14, wherein the conductive transparent electrode layer comprises a material selected from the group consisting of indium tin oxide (ITO), tin oxide, AgO, ZnO—

(Ga₂O₃ or Al₂O₃), fluorine tin oxide (FTO), and mixtures thereof.

25. The method of claim 14, wherein the first electrode comprises a plurality of first electrodes spaced apart by an interval ranging from about 2.5 to about 8 mm from each other.