Patent ID: 8829332

Claim:
A photovoltaic device comprising: an island including a base epitaxial portion having a first doping level and an upper epitaxial portion disposed on the base epitaxial portion and having a second doping level that is lower than said first doping level, said island being disposed between first and second side walls defined by one or more trench regions that respectively extend from said base epitaxial portion to an upper surface of said upper epitaxial portion; a light-sensitive diode disposed on said island, said light-sensitive diode including a first P+ doped region formed by a P+ dopant diffused into said upper epitaxial portion, an intrinsic region of said upper epitaxial portion, and a first N+ doped region formed by an N+ dopant diffused into said upper epitaxial portion, said intrinsic region being disposed between said first P+ doped region and said first N+ doped region; wherein the base epitaxial portion of said island is entirely disposed on a porous silicon region.