In an array of such cells the edge of the second conductive film of one cell can overlap the edge of the first conductive film of an adjacent film for connecting the cells in series. In one aspect of the invention the films are thin enough to be transparent.
In another aspect, a plurality of semi-transparent films are stacked to absorb selective portions of the spectrum.
In another aspect, a technique of stacking thin films using diagonal displacement of a mask provides successive layers with exposed and covered edges for suitable electrical connections.
1. Solar cells and arrays of solar cells are made as thin films on insulating substrates. In an exemplary embodiment, a thin conductive film is deposited on glass and a semi-conductor film is deposited over the metal. The semi-conductor film has a P-N junction parallel to the substrate. Another conductive film is deposited over the semi-conductor and is insulated from the first conductive film. Contacts made to edges of the conductive films form solar cells.
2. A thin Solar cell is a second generation solar cell that is made by depositing one or more thin layers, or thin film (TF) of photovoltaic material on a substrate, such as glass, plastic or metal. Thin-film solar cells are commercially used in several technologies, including cadmium telluride (CdTe), copper indium gallium diselenide (CIGS), and amorphous thin-film silicon (a-Si, TF-Si).
https://www.google.com/patents/US4400577 (1.); https://en.wikipedia.org/wiki/Thin-film_solar_cell (2.)