Single-crystalline n-type silicon nanowire (n-SiNW) arrays have been synthesized by electroless metal deposition on a silicon wafer chip in an ionic Ag/HF solution through selective etching. The photoelectrochemical properties of the SiNW arrays were studied (under 40 mW cm(-2) white illumination conditions) in an aqueous electrolyte [with Fe (CN)(6)(4-)/Fe(CN)(6)(3-) redox couple] and compared to those of its untreated bare polished Si sample counterpart (n-Si). The open-circuit photovoltage was lower, on average, for SiNWs array photoelectrodes, while short-circuit current density, fill factor, and overall energy conversion efficiency of the SiNWs array photoelectrodes were generally superior to those of the n-Si junction devices. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3089318] All rights reserved.