Helmholtz-zentrum Berlin Fuer Materialien Und Energie Gmbh

Helmhotz-zentrum Berlin Fuer Materialien Und Energie Gmbh

Helmholtz-zentrum Berlin Für Materialien Und Energie Gmbh

Rolf Stangl

Bernd Rech

Klaus Lips

Stefan Gall

Lars Korte

A method for the production of a wafer-based, back-contacted heterojunction solar cell includes providing at least one absorber wafer. Metallic contacts are deposited as at least one of point contacts and strip contacts in a predetermined distribution on a back side of the at least one absorber wafer. The contacts have steep flanks that are higher than a cumulative layer thickness of an emitter layer and an emitter contact layer and are sheathed with an insulating sheath. The emitter layer is deposited over an entire surface of the back side of the at least one absorber wafer. The emitter contact layer is deposited over an entire surface of the emitter layer so as to form an emitter contact system. At least one of the emitter layer and the emitter contact layer is selectively removed so as to expose the steep flanks of the contacts that are covered with the insulating sheath. An insulation layer is deposited over an entire surface of the emitter contact layer so as to provide a narrow contact web at an edge of the at least one absorber wafer. End areas of the steep flanks of the contacts that are covered by the insulation layer are exposed. At least one of an absorber contact layer and an absorber contact grid is deposited over an entire surface of the insulation layer and over the exposed end areas of the steep flanks so as to form the absorber contact system, so as to provide the heterojunction solar cell with the contact web and with the at least one of an absorber contact layer and an absorber contact grid of the absorber contact system.

Method for the production of a wafer-based, back-contacted heterojunction solar cell and heterojunction solar cell produced by the method

A thin-film solar module contacted on one side includes a support layer, a photoactive absorber layer and at least one dopant layer deposited over a surface area of at least one side of the absorber layer so as to form a thin-film packet that is divided into thin-film solar cell areas by insulating separating trenches. The thin-film solar module includes first and second contact systems. The first contact system includes contacts connected by an outer contact layer. The second contact system consists of an inner contact layer covering a side of the solar cell areas that face away from the support layer so as to separately discharge excess charge carriers generated by incident light in the absorber layer. The second contact system includes structures that surround and electrically insulate the contacts, which extend through the inner contact layer from the outer contact layer. The first and second contact systems are electrically conductive and connected in series by series contacts in interconnection areas and electrically insulated from each other by an insulation layer outside of the interconnection areas.

Thin-film solar module contacted on one side and having an inner contact layer

A solar cell includes a photoactive, semiconductive absorber layer configured to generate excess charge carriers of opposed polarity by light incident on a front of the absorber layer during operation. The absorber layer is configured to separate and move, via at least one electric field formed in the absorber layer, the photogenerated excess charge carriers of opposed polarity over a minimal effective diffusion length L. The absorber layer has a thickness Lof 0&#x3c;L&#x2266;L. First contact elements are configured to remove the excess charge carriers of a first polarity on a rear of the absorber layer. Second contact elements are configured remove the excess charge carriers of a second polarity on the rear of the absorber layer. At least one undoped, electrically insulating second passivation region is disposed in an alternating, neighboring arrangement with a first passivation region on the rear of the absorber layer.

Solar cell comprising neighboring electrically insulating passivation regions having high surface charges of opposing polarities and production method

In an embodiment of the present invention, a single-sided contact solar cell includes an absorber layer with plated-through holes; an emitter layer disposed on a first side of the absorber layer, the emitter layer including one or more semiconductor materials having different dopants; a field passivation layer disposed on a second side of the absorber layer; a contact grid covered on a top surface thereof with an insulation layer and electrically connected to a first end of the plated-through holes; and a contact layer. The contact grid and contact layer are disposed together on one side of the absorber layer and insulated with respect to each other and electrically contacted from outside of the solar cell. The contact grid is disposed between the absorber layer and the emitter layer or the field passivation layer, and the contact layer is disposed on the emitter layer or on the field passivation layer so that both the contact grid and contact layer are disposed on a top surface of the solar cell. The emitter layer or the field passivation layer is electrically connected to a second end of the plated-through holes. Where the second end of the plated-through holes is electrically connected to the emitter layer, the absorber layer and the contact grid are electrically insulated from each other.

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Berlin, Germany

Rolf Stangl