Concrete solar cell

Abstract

An inexpensive, robust concrete solar cell (10) comprises a photovoltaic material embedded in and extending beyond front and rear major surfaces (18 and 16) of a matrix layer (14). The matrix layer typically comprises a high-strength, cementitious material, such as a macrodefect-free cement, reinforced with electrically nonconductive fibers (54) distributed throughout the matrix layer. The photovoltaic material comprises particles (12) of high-resistivity single crystal silicon, typically ball milled from ingot sections unsuitable for slicing into silicon wafers. An aluminum sheet (28) attached to the rear major surface provides electrical contact to one of two electrical region (22 and 24) of the semiconductor particle, and a translucent conductive layer (30) on the front major surface provides electrical contacts to the second electrical region. Overlapping electrically conductive reinforcing fibers (52) are embedded at the front major surface of the matrix layer to decrease the sheet resistivity of the surface and to inhibit the formation of surface cracks. Digitated electrode (32) further improves surface conductivity for conducting current off the cell. A voltage is generated between the two conductive layers when light incident on the semiconductor particles through the translucent conductive layer creates charge carriers that are propelled toward the conductive layers by a built-in field.

Dependencies are inferred from the claim text.