Solar battery

Abstract

The invention provides a flexible solar battery having a high photoelectric conversion efficiency and no aging. A cell (10) (unit cell) comprises a lower electrode layer (2) (Mo electrode layer) formed on a flexible reconstituted mica substrate (1), a light absorption layer (3) (CIGS light absorption layer) containing copper, indium, gallium, and selenium, a buffer layer thin film (4) having a high resistance and formed of, for example, InS, ZnS, or CdS on the light absorption layer (3), and an upper electrode layer (5) (TCO) formed of, for example, ZnOAl. In order to connect a plurality of the unit cells (10) in series, a contact electrode portion (6) for connecting the upper electrode layer (5) and the lower electrode layer (2) is also formed. The contact electrode portion (6) has a larger Cu / In ratio than that of the light absorption layer (3). In other words, the contact electrode portion (6) is formed with a smaller amount of In and has a p+ type or conductor property with respect to the light absorption layer (3) that is a p-type semiconductor.

Description

technical field [0001] The present invention relates to a chalcopyrite-type solar cell as a compound-based solar cell, and more particularly, to a solar cell using a flexible substrate and having an electrode for connecting an upper electrode and a lower electrode. Background technique [0002] Solar cells that receive light and convert it into electrical energy are classified into bulk type (series) and thin-film type (series) according to the thickness of the semiconductor. Among them, thin films are solar cells in which a semiconductor layer has a thickness of several 10 μm to several μm or less, and are classified into silicon thin films and compound thin films. Compound thin films include II-VI compounds, chalcopyrite and other types, some of which have been commercialized so far. Among them, chalcopyrite solar cells belonging to chalcopyrite are also called CIGS (Cu(InGa)Se) thin-film solar cells, or CIGS solar cells are also called I-III-VI, depending on the material...

AI Technical Summary

Problems solved by technology

On the contrary, glass substrates have the following disadvantages: low melting point, difficulty in setting the heat treatment (Anneal) temperature high in the vapor phase selenization process, so the light energy conversion efficiency will be suppressed low; the substrate is thick and heavy , so the equipment used in manufacturing must also be enlarged; the weight of the module is also large, and the handling of the product is inconvenient; the substrate can hardly be deformed, so mass production processes such as the continuous tape (Roll to Roll) process cannot be used

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