Chalcopyrite Cu(In0.8Ga0.2)S-2 (CIGS) nanowires were synthesized by using a relatively simple and convenient electrospun process. From the reactions of CuCl, InCl3, GaCl3 and thiocarbamide as a precursor, semiconductor CIGS nanowires with diameter in the range of 60-80 nm were obtained for Polyvinylbutyral/CIGS precursor ratios of 40% at an applied voltage of 25 kV after annealing treatment at 600 degrees C for 3 h. A probable formation mechanism of chalcopyrite quaternary semiconductor nanowires is proposed based on a series of comparative experiments conducted under various reaction conditions. (C) 2011 Elsevier B.V. All rights reserved.