The dark current-voltage characteristics of p-SXSe100-x/n-Si heterojunctions, with x = 0, 2.5, 5.8 and 7.28 at.% S have been investigated in a temperature range from 303 to 383 K. The operating conduction mechanisms were found to be the thermionic-assisted tunnelling and pure tunnelling for low and high forward bias, respectively. Under reverse biasing, the operating conduction mechanism is the generation recombination mechanism. Analysis of the photovoltaic characteristics at room temperature and under illumination of similar to 477 Wm(-2) leads to the determination of some solar cell parameters, such as, the short circuit current density (J(SC) approximate to 165, 140, 116.7 and 103.3 A/m(2)), the open-circuit voltage (V-oc approximate to 0.36, 0.35, 0.32 and 0.31 V), the fill factor (FF approximate to 0.344, 0.372, 0.360 and 0.378) and the power conversion efficiency (eta approximate to 4.278, 3.816, 2.814 and 2.534%) for x = 0, 2.5, 5.8 and 7.28 at.% S, respectively. (c) 2006 Elsevier Ltd. All rights reserved.