Abstract
We inexpensively fabricated vertically aligned Si nanowire solar cells using metal-induced electroless etching and a novel doping technique. Codoping of boron and phosphorus was achieved using a spin-on-doping method for the simultaneous formation of a front-side emitter and a back surface field in a one-step thermal cycle. Nickel electroless deposition was also performed in order to form a continuous metal grid electrode on top of an array of vertically aligned Si nanowires. A highly dense array of Si nanowires with low reflectivity was obtained using Ag nanoparticles of optimal size (60-90 nm). We also obtained an open circuit voltage of 544 mV, a short circuit current of 14.68 mA/cm(2), and a cell conversion efficiency of 5.25% at 1.5AM illumination. The improved photovoltaic performance was believed to be the result of the excellent optical absorption of the Si nanowires and the improved electrical properties of the electroless deposited electrode. (C) 2010 The Japan Society of Applied Physics