Solar cell emitter region fabrication using ion implantation

Patent metadata

Field	Value
Publication number	US-9716205-B2
Application number	US-201615197616-A
Country	US
Kind code	B2
Filing date	Jun 29, 2016
Priority date	Dec 9, 2013
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

Methods of fabricating solar cell emitter regions using ion implantation, and resulting solar cells, are described. In an example, a method of fabricating alternating N-type and P-type emitter regions of a solar cell involves forming a silicon layer above a substrate. Dopant impurity atoms of a first conductivity type are implanted, through a first shadow mask, in the silicon layer to form first implanted regions and resulting in non-implanted regions of the silicon layer. Dopant impurity atoms of a second, opposite, conductivity type are implanted, through a second shadow mask, in portions of the non-implanted regions of the silicon layer to form second implanted regions and resulting in remaining non-implanted regions of the silicon layer. The remaining non-implanted regions of the silicon layer are removed with a selective etch process, while the first and second implanted regions of the silicon layer are annealed to form doped polycrystalline silicon emitter regions.

First claim

What is claimed is:

1. A back contact solar cell, comprising:
a monocrystalline silicon substrate having a light-receiving surface and a back surface;
a thin dielectric layer disposed on the back surface of the monocrystalline silicon substrate;
a polycrystalline silicon emitter region disposed on the thin dielectric layer, the polycrystalline silicon emitter region doped with impurity atoms;
a carbosilane layer disposed on, and aligned with, the polycrystalline silicon emitter region; and
a conductive contact structure disposed through the carbosilane layer and on the polycrystalline silicon emitter region.

2. The back contact solar cell of claim 1 , wherein the carbosilane layer is also doped with the impurity atoms.

3. The back contact solar cell of claim 1 , wherein the polycrystalline silicon emitter region is hydrogenated.

4. The back contact solar cell of claim 1 , further comprising texturized portions of the substrate adjacent to the polycrystalline silicon emitter region.

5. The back contact solar cell of claim 1 , wherein the impurity atoms are boron atoms.

6. The back contact solar cell of claim 1 , wherein the impurity atoms are phosphorous atoms.

7. A solar cell, comprising:
a thin dielectric layer disposed on a surface of a substrate;
a silicon layer disposed on the thin dielectric layer, the silicon layer doped with impurity atoms;
a carbon carbosilane layer disposed on the silicon layer, the carbon carbosilane layer aligned with and separate and distinct from the silicon layer; and
a conductive contact structure disposed through the carbon carbosilane layer and on the silicon layer.

8. The solar cell of claim 7 , wherein the carbon carbosilane layer is also doped with the impurity atoms.

9. The solar cell of claim 7 , wherein the silicon layer is hydrogenated.

10. The solar cell of claim 7 , further comprising texturized portions of the substrate.

11. The solar cell of claim 7 , wherein the impurity atoms are boron atoms or phosphorous atoms.

Assignees

• Weidman Timothy
• Smith David D
• Sunpower Corp

Inventors

• Weidman Timothy
• Smith David D

Classifications

• Y02E10/546

  Polycrystalline silicon PV cells · CPC title

• Y02E10/547

  Monocrystalline silicon PV cells · CPC title

• H01L31/1872

  Electricity · mapped topic

• H01L31/1876

  Electricity · mapped topic

• H01L31/035272

  Electricity · mapped topic