Silicon nanowire solar cells grown by PECVD

Silicon nanowires offer an opportunity to improve light trapping in low-cost silicon photovoltaic cells. We have grown radial junctions of hydrogenated amorphous silicon over p-doped crystalline silicon nanowires in a single pump-down plasma enhanced chemical vapor deposition process on glass substrates. By using Sn catalysts and boosting p-type doping in the nanowires, the open-circuit voltage of the devices increased from 200 to 800 mV. Light trapping was optimized by extending the length of nanowires in these devices from 1 to 3 mu n, producing currents in excess of -13 mA cm(-2) and energy conversion efficiencies of 5.6%. The advantages of using thinner window layers to increase blue spectral response were also assessed. (C) 2011 Elsevier B.V. All rights reserved.