Solar cell having an emitter region with wide bandgap semiconductor material

Patent metadata

Field	Value
Publication number	US-10957809-B2
Application number	US-201916692890-A
Country	US
Kind code	B2
Filing date	Nov 22, 2019
Priority date	Mar 23, 2012
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

Solar cells having emitter regions composed of wide bandgap semiconductor material are described. In an example, a method includes forming, in a process tool having a controlled atmosphere, a thin dielectric layer on a surface of a semiconductor substrate of the solar cell. The semiconductor substrate has a bandgap. Without removing the semiconductor substrate from the controlled atmosphere of the process tool, a semiconductor layer is formed on the thin dielectric layer. The semiconductor layer has a bandgap at least approximately 0.2 electron Volts (eV) above the bandgap of the semiconductor substrate.

First claim

What is claimed is:

1. A solar cell, comprising:
a semiconductor substrate;
a thin dielectric layer disposed on the semiconductor substrate;
a first emitter region of a first conductivity type disposed on the thin dielectric layer, wherein the first emitter region comprises polycrystalline silicon;
a first oxide layer disposed on the semiconductor substrate; and
a second emitter region of a second conductivity type disposed on the first oxide layer, the second conductivity type opposite the first conductivity type, wherein the second emitter region comprises polycrystalline silicon, wherein a portion of the second emitter region is partially disposed over the first emitter region.

2. The solar cell of claim 1 , wherein the portion of the second emitter region is partially disposed over the thin dielectric layer.

3. The solar cell of claim 1 , wherein a portion of the first oxide layer is partially disposed over the first emitter region.

4. The solar cell of claim 1 , wherein a portion of the first oxide layer is partially disposed over the thin dielectric layer.

5. A solar cell, comprising:
a semiconductor substrate;
a thin dielectric layer disposed on the semiconductor substrate;
a first emitter region of a first conductivity type disposed on the thin dielectric layer, wherein the first emitter region comprises polycrystalline silicon;
a first oxide layer disposed on the semiconductor substrate; and
a second emitter region of a second conductivity type disposed on the first oxide layer, the second conductivity type opposite the first conductivity type, wherein the second emitter region comprises polycrystalline silicon and a portion of the second emitter region is partially disposed over the first emitter region.

6. The solar cell of claim 5 , wherein the portion of the second emitter region is partially disposed over the thin dielectric layer.

7. The solar cell of claim 5 , wherein a portion of the first oxide layer is partially disposed over the first emitter region.

8. The solar cell of claim 5 , wherein a portion of the first oxide layer is partially disposed over the thin dielectric layer.

9. The solar cell of claim 5 , wherein the first conductivity type is N-type, and the second conductivity type is P-type.

10. The solar cell of claim 5 , wherein the first conductivity type is P-type, and the second conductivity type is N-type.

11. The solar cell of claim 5 , wherein the second emitter region has a dopant concentration approximately in the range of 1×1017-1×1021 atoms/cm3.

12. The solar cell of claim 5 , wherein the first oxide layer comprises silicon oxide.

13. The solar cell of claim 5 , further comprising:
a second oxide layer disposed over a light receiving surface of the semiconductor substrate;
an amorphous silicon layer disposed on the second oxide layer; and
an anti-reflective coating (ARC) layer disposed on the amorphous silicon layer, the ARC layer comprising silicon nitride.

14. A solar cell, comprising:
a semiconductor substrate;
a thin dielectric layer disposed on the semiconductor substrate;
a first emitter region of a first conductivity type disposed on the thin dielectric layer, wherein the first emitter region comprises polycrystalline silicon;
a layer of doping material disposed on the first polycrystalline emitter region;
a first oxide layer disposed on the semiconductor substrate; and
a second emitter region of a second conductivity type disposed on the first oxide layer, the second conductivity type opposite the first conductivity type, wherein the second emitter region comprises polycrystalline silicon and a portion of the second emitter region is partially disposed over the first emitter region.

15. The solar cell of claim 14 , wherein the layer of doping material comprises a positive-type doping material.

16. The solar cell of claim 15 , wherein the positive-type doping material comprises boron.

17. The solar cell of claim 14 , wherein a portion of the second emitter region is partially disposed over the thin dielectric layer.

18. The solar cell of claim 14 , wherein the first conductivity type is N-type, and the second conductivity type is P-type.

19. The solar cell of claim 14 , wherein the first oxide layer comprises silicon oxide.

Assignees

• Sunpower Corp

Inventors

• Swanson Richard M
• Bunea Marius M
• Johnson Michael C
• Smith David D
• Shen Yu-Chen
• Cousins Peter J
• Dennis Tim

Classifications

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title

• H10F10/146

  Back-junction photovoltaic cells, e.g. having interdigitated base-emitter regions on the back side · CPC title

• H10F19/00

  Integrated devices, or assemblies of multiple devices, comprising at least one photovoltaic cell covered by group H10F10/00, e.g. photovoltaic modules · CPC title

• H10F77/166

  Amorphous semiconductors · CPC title

• H10F77/164

  Polycrystalline semiconductors · CPC title