Carbon nanotube based silicon photovoltaic device

A photovoltaic device, comprising:

• a silicon substrate having a front surface and a rear surface, wherein the silicon substrate is n-type silicon adapted to generate electron carriers;
• an intrinsic layer disposed directly on the front surface of the silicon substrate;
• a carbon nanotube structure disposed on and in direct contact with the intrinsic layer, and completely separated from the silicon substrate, the carbon nanotube structure comprising a plurality of successively oriented carbon nanotube segments joined end-to-end by van der Waals attractive force, wherein the plurality of carbon nanotubes segments comprises a plurality of carbon nanotubes substantially parallel to each other and parallel to the front surface of the silicon substrate, the carbon nanotube structure is adapted to absorb light and then generate hole carriers;
• and
• a first electrode disposed on the rear surface of the silicon substrate.