Thursday, September 18, 2008


Pub. No.:
International Application No.:

Publication Date:18.09.2008 International Filing Date:10.03.2008
IPC: H01L 31/07 (2006.01), H01L 31/028 (2006.01), H01L 31/036 (2006.01)
Applicants:WISCONSIN ALUMNI RESEARCH FOUNDATION [US/US]; 614 Walnut Street, 13th Floor, Madison, Wisconsin 53726 (US) (All Except US).
LAGALLY, Max [US/US]; 5110 Juneau Road, Madison, Wisconsin 53705 (US) (US Only).
LIU, Feng [US/US]; 6681 South Candle Cove, Salt Lake City, Utah 84121 (US) (US Only).


[0006] The present invention encompasses graphite-based photovoltaic cells and methods for generating electricity from these cells. In these photovoltaic cells, spatially separated stacks of graphite, each comprising a plurality of vertically stacked semiconducting graphcnc(sic graphene) sheets, serve as a photovoltaic material bridging electrical contacts. The graphcnc(sic graphene) sheets, or "nanoribbons," have nanoscale-widtli(sic width) dimensions such that the band gap of each sheet depends on the width of the sheet. Thus, by incorporating graphenc(sic graphene) sheets having different widths, and thereby different band gaps, into the photovoltaic cell, the cell can be designed to absorb efficiently across the solar spectrum. The result is a photovoltaic cell that is efficient and inexpensive to manufacture.

The present invention uses lithographically patterned graphite stacks as the basic building elements of an efficient and economical photovoltaic cell. The basic design of the graphite-based photovoltaic cells includes a plurality of spatially separated graphite stacks, each comprising a plurality of vertically stacked, semiconducting graphene sheets (carbon nanoribbons) bridging electrically conductive contacts.