Patent ID: 7592201

Claim:
A method of forming a photovoltaic device structure in a silicon film deposited on a glass substrate, the film comprising an n + type region having n + type silicon closest to the glass, a lightly doped region over the n + type region, and a p + type region having p + type silicon over the lightly doped region, the method comprising: a) dividing the silicon film into a plurality of cell regions by forming cell isolation grooves; b) forming a mask of organic resin in a layer over the silicon film; c) forming a first set of openings in the mask in locations where contacts to the n + type region are required; d) etching the silicon film through the first set of openings to expose at least some of the n + type silicon; e) placing the substrate into an atmosphere comprising a vapour of a solvent of the organic resin whereby the organic resin softens and re-flows to reduce the size of each opening of the first set of opening in the mask; f) forming a second set of openings in the mask in further locations where contacts to the p + type region are required; g) forming a metal layer over a surface of the mask and extending the metal into each opening of the first and second sets of openings to contact the n + type and p + type silicon, the metal being isolated from the p + type silicon by the organic resin in the first set of openings; h) forming metal isolation grooves in the metal layer to separate the contacts to the p + type silicon and the n + type silicon within each cell, and wherein the first and second sets of openings in the mask are each formed by depositing a reactive material onto the surface of the mask in a predetermined pattern, comprising: i) placing the photovoltaic device structure on a stage; j) locating an inkjet print device over the photovoltaic device structure and in close proximity thereto, the ink-jet print device and stage being moveable relative to one another; k) supplying the ink-jet print device with the reactive material; l) moving the photovoltaic device structure and the ink-jet print device relative to one another; and m) controlling the ink-jet print device to deposit predetermined amounts of the reactive material onto the surface of the mask in the predetermined pattern as the photovoltaic device structure and the ink-jet print device move relative to one another.