In this work we present light effects on chemically passivated silicon surface. Di-iodine-ethanol (I-E) mixtures were used to passivate silicon dangling bonds. The passivation quality is sensitive to both silicon surface state and light irradiation. The minority carrier lifetime values vary from 2 mu s for unpassivated surfaces to about 40 mu s for chemically passivated ones. FTIR investigations show that light irradiation catalyses the passivation effect by forming the silicon-ethoxylate group (-Si-O-C2H5). We suggest a mechanism to explain the passivation effect based on carrier-induced dissociation of I-2. (C) 2013 Elsevier B.V. All rights reserved.