US Patent 7799988 - Point contact nanowire solar cell

http://ip.com/patent/US7799988

Most solar cells are based on planar semiconductor wafers which have a maximum theoretical efficiency due to the bandgap of the semiconductor material. This patent proposes an alternative solar cell construction based on the formation of metallic nanowires or nanotubes as rectifying antennas to convert the visible spectrum into a source of DC current and which may improve the theoretical maximum efficiency. Claim 1 reads:

1. A device for receiving and converting incident radiation into DC current, comprising:

a transparent conductor;

at least one point-contact diode, the at least one point-contact diode having a nanowire providing a receiving antenna function and a rectification function, the nanowire including a sharp edge, the nanowire tapering and being narrowest at the sharp edge;

a thin insulating layer, situated between the transparent conductor and the nanowire; and

a point-contact junction, at which the sharp edge of the nanowire contacts the thin insulating layer.