▎ 摘　　要

NOVELTY - A photovoltaic cell comprises contact with electrically conductive material; another contact with another electrically conductive material; and spatially separated graphite stack that bridges the contacts, where the junctions between conductive material and graphene sheets form Schottky barriers for electrons or holes. The graphite stack comprises vertically stacked semiconducting graphene sheets. USE - A photovoltaic cell for producing electricity (claimed). ADVANTAGE - The cell absorbs at wavelengths across the full solar spectrum of solar radiation by incorporating graphene sheets having different widths and different band gaps. The cell can produce power densities of greater than or equal to 50 W/m2, even without solar concentrator. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of an electron confinement in carbon nanotube and carbon nanoribbon.