Backplane reinforcement and interconnects for solar cells

A method for forming a back contact solar cell, comprising:

• forming a porous silicon seed and release layer with at least two different porosities on the surface of a crystalline silicon template;
• depositing an epitaxial silicon layer on said porous silicon seed and release layer, said epitaxial silicon layer having a thickness less than 100 microns and an in-situ-doped base region, and said epitaxial silicon layer comprising doped emitter regions and a backside surface forming emitter and base contact regions with said in-situ-doped base regions and said doped emitter region;
• depositing a first layer of electrically conductive metal having an interdigitated pattern of base electrodes and emitter electrodes on said backside surface of said epitaxial silicon layer, said first layer of electrically conductive metal having a thickness less than 2 microns;
• forming electrically conductive adhesive emitter plugs and base plugs on said first layer of electrically conductive metal, said emitter plugs and base plugs providing emitter electrical connections and base electrical connections for a backplane;
• laminating said backplane to said first layer of electrically conductive metal by said conductive adhesive emitter plugs and base plugs, said backplane comprising a second layer of electrically conductive metal having an interdigitated pattern of base electrodes and emitter electrodes and connected to said first layer of electrically conductive metal by said conductive adhesive emitter plugs and base plugs thereby forming an electrical interconnect, said second layer of electrically conductive metal having a thickness in the range of 25 to 150 microns, and a backplane plate attached to said second layer of electrically conductive metal;
• and
• releasing said epitaxial silicon layer from said silicon template along said porous silicon release layer.