Heterojunction solar cell incorporating vertically-aligned nanowires

A low-cost method is provided for forming a photovoltaic device, which is a high-performance nanostructured multijunction cell. The multiple P-N junctions or P-I-N junctions are contiguously joined to form a single contiguous P-N junction or a single contiguous P-I-N junction. The photovoltaic device integrates vertically-aligned semiconductor nanowires including a doped semiconductor material with a thin silicon layer having an opposite type of doping. This novel hybrid cell can provide a higher efficiency than conventional photovoltaic devices through the combination of the enhanced photon absorptance, reduced contact resistance, and short carrier transport paths in the nanowires. Room temperature processes or low temperature processes such as plasma-enhanced chemical vapor deposition (PECVD) and electrochemical processes can be employed for fabrication of this photovoltaic device in a low-cost, scalable, and energy-efficient manner.