(thanks to donpat, Raging Bull private APNT forum)

Kind Code A1
Novak; James P. ; et al. January 17, 2013
SURFACE-MODIFIED NANOPARTICLE INK FOR PHOTOVOLTAIC APPLICATIONS

Abstract

Described herein is a novel material that easily penetrates silicon nitride-based anti-reflective coatings, forming a high quality electrical contact. A method for metallization on a solar cell includes depositing a passivation layer on a silicon substrate of a solar cell, depositing derivatized metal particles onto the passive layer, heating the substrate of the solar cell to migrate surface coatings from the derivatized metal particles onto the passivation layer creating a diffusion Channel through passivation layer to the silicon substrate, and as the metal particles melt due to the heating on the substrate, the melted metal diffuses through the diffusion channel forming a metallic content with the silicon substrate.

Inventors:
Novak; James P.; (Austin, TX) ; Li; Yunjun; (Austin, TX)

Assignee:
APPLIED NANOTECH HOLDINGS, INC.
Austin
TX

Serial No.: 545699
Series Code: 13
Filed: July 10, 2012

[0006] A prominent challenge in the manufacture of silicon solar cells is the formation of the top contacts. A quality ohmic contact is required for proper solar cell function however, the ARC layer is, by nature, highly resistant to chemicals; for example, silicon nitride is commonly used as a harrier layer to metal penetration in the fabrication of electronic devices. The placement of metallic pastes on top of a silicon nitride layer creates challenges whereby the metal cannot easily make electrical contact with the silicon underneath the ARC. Metallic pastes used for the formation Of top contacts contain complex glass frit, materials, whereby the glass frit melts at high temperature, reacts with the nitride passivation layer and provides a route for metal diffusion to establish a contact.

Claims
1. A method for metallization on a substrate comprising: depositing a passivation layer on a silicon substrate; depositing derivatized metal particles onto the passive layer; heating the substrate of the solar cell to migrate surface coatings from the derivatized metal particles onto the passivation layer creating a diffusion channel through the passivation layer to the silicon substrate; and as the metal particles melt due to the heating on the substrate, the melted metal diffuses through the diffusion channel forming a metallic content with the silicon substrate.

http://is.gd/aFnS4u