Fabrication of thin-film photovoltaic cells with reduced recombination losses

A method of fabricating photovoltaic cell contacts, the method comprising:

• providing a block copolymer layer above an electrical contact layer of a photovoltaic cell, the block copolymer layer being self-assembled by phase segregation to comprise multiple structures of a first polymer material surrounded, at least in part, by a second polymer material;
• selectively etching the block copolymer layer to remove the multiple structures, forming holes in the block copolymer layer;
• using the holes in the block copolymer layer to facilitate providing electrical contacts between a light absorption layer of the photovoltaic cell and the electrical contact layer of the photovoltaic cell;
• providing, before depositing the block copolymer layer, a patterned sacrificial layer above the electrical contact layer, the patterned sacrificial layer comprising patterned openings through the patterned sacrificial layer;
• and
• the providing of the block copolymer layer comprising depositing the block copolymer layer over the patterned sacrificial layer, including within the patterned openings, wherein the multiple structures of the first polymer material, and thus the holes in the block copolymer layer, are formed within the patterned openings in the patterned sacrificial layer.

A method of fabricating a photovoltaic cell comprising:

• providing an electrical contact layer with a passivation layer over the electrical contact layer, the passivation layer comprising a dielectric material;
• providing a block copolymer layer over the passivation layer, the block copolymer layer being self-assembled by phase segregation to comprise multiple structures of a first copolymer material surrounded, at least in part, by a second copolymer material;
• selectively etching the block copolymer layer to remove the multiple structures, forming holes in the block copolymer layer;
• etching the passivation layer through the holes in the block copolymer layer to form contact openings through the passivation layer;
• and
• providing a light absorption layer of the photovoltaic cell, the light absorption layer extending into the contact openings through the passivation layer and directly physically contacting the electrical contact layer, making electrical connection with the electrical contact layer via multiple point contacts, the multiple point contacts reducing recombination losses at the light absorption layer interface with the electrical contact layer, wherein the electrical contact layer is a back contact layer or a front contact layer to the light absorption layer of the photovoltaic cell.