Solar cell interconnection by discrete conductive regions

A method of fabricating a thin film solar module, comprising:

• providing a plurality of first electrode pads on a substrate by depositing a conductive film on the substrate, depositing a thickened metal-containing portion in electrical contact with the conductive film and patterning the conductive film;
• depositing at least one semiconductive layer onto the first electrode pads to define a photovoltaic region corresponding to each first electrode pad;
• depositing a plurality of second electrode pads onto the semiconductor layer, each second electrode pad overlying one of the photovoltaic regions and overlapping the first electrode pad of an adjacent photovoltaic region over a preselected area which includes the thickened metal-containing portion of said first electrode pad;
• and
• establishing a plurality of localized conductive paths through the semiconductive layer from each second electrode pad to the thickened metal-containing portion of the first electrode pad that it overlaps to connect at least two of the photovoltaic regions in series, the conductive paths comprising discrete conductive regions spaced apart from each other within the plane of the module.

A method of fabricating a thin film solar module comprising:

• providing a plurality of first electrode pads on a substrate, each of said first electrode pads having a thin film portion and a thickened metal-containing portion adjacent to an edge of the thin film portion;
• depositing at least one semiconductive layer onto the first electrode pads to define a photovoltaic region corresponding to each first electrode pad;
• depositing a plurality of second electrode pads onto the semiconductor layer, each second electrode pad overlying one of the photovoltaic regions and overlapping the first electrode pad of an adjacent photovoltaic region over a preselected area containing the respective metal-containing portion;
• and
• applying laser pulses to the areas of electrode overlap at the locations of the metal-containing portions to establish a plurality of localized conductive paths from each second electrode pad to the metal-containing portion of the first electrode pad that it overlaps and thus connect at least two of the photovoltaic regions in series, the conductive paths comprising discrete conductive regions spaced apart from each other within the plane of the module.

A method of fabricating a thin film solar module comprising:

• providing a plurality of front electrode pads on a substrate;
• depositing at least one semiconductive layer onto the front electrode pads to define a photovoltaic region corresponding to each front electrode pad;
• depositing over the semiconductive layer a first conductive film of a first conductive material which tends not to form a stable ohmic contact with the front electrode pads;
• producing a plurality of discrete cavities through the first conductive film and the photovoltaic regions of the semiconductive layer to each front electrode pad, the cavities being located adjacent to edges of the photovoltaic regions at preselected areas over which the photovoltaic regions are to be interconnected;
• depositing a second conductive material over the semiconductive layer and into the cavities to form a second conductive film and a plurality of discrete conductive regions within the cavities, the second conductive material being selected to form a stable ohmic contact with the first conductive film and the front electrode pads;
• and
• patterning the first and second conductive films into a plurality of back electrode pads so that each back electrode pad overlies on of the photovoltaic regions and overlaps the front electrode pad of an adjacent photovoltaic region over said preselected area.

A thin film solar module comprising:

• a plurality of first electrode pads on a substrate, each first electrode pad comprising a conductive film and a thickened metal-containing portion in electrical contact therewith;
• at least one semiconductive layer deposited over the first electrode pads to establish a photovoltaic region correspondong to each first electrode pad;
• a plurality of second electrode pads deposited onto the semiconductive layer, each second electrode pad overlying one of the photovoltaic regions and overlapping the first electrode pad of an adjacent photovoltaic region over a preselected area which includes the thickened metal-containing portion of said first electrode pad;
• and
• a plurality of localized conductive paths extending through the semiconductive layer from each second electrode pad to the metal-containing portion of the first electrode pad that it overlaps to connect at least two of the photovoltaic regions in series, the conductive paths comprising discrete conductive regions spaced apart from each other within the plane of the module and formed by localized heating of the module at a plurality of spaced locations within the areas of electrode overlap.

A thin film solar module comprising:

• a plurality of front electrode pads on a substrate;
• at least one semiconductive layer deposited over the front electrode pads to define a photovoltaic region corresponding to each front electrode pad;
• a plurality of back electrode pads deposited onto the semiconductor layer, each back electrode pad having a first conductive film portion overlying one of the photovoltaic regions and overlapping the front electrode pad of an adjacent photovoltaic region over a preselected area containing the respective metal-containing portion, said first conductive film portion being of a first conductive material which tends not to form a stable ohmic contact with the front electrode pads;
• a plurality of discrete cavities through the first conductive film and the photovoltaic regions extending to each front electrode pad, the cavities being located adjacent to edges of the photovoltaic regions at preselected areas over which the photovoltaic regions are to be interconnected;
• the back electrode pads further comprising a layer of a second conductive material deposited over the first conductive film and into the cavities to form a second conductive film and a plurality of discrete conductive regions connecting each back electrode pad to the front electrode pad that it overlaps, the second conductive material being selected to form a stable ohmic contact with the first conductive film and the front electrode pads.