The performance or pyrite (FeS2) in photovoltaic devices is forecast for various device structures by means of numerical modelling. The physical model is based on recent investigations or thin-film pyrite layers, allowing a forecast for realistically achievable (non-deal) material parameters. It is confirmed that, in a feasible form, pyrite possesses electrical properties that are suitable for photovoltaic energy conversion. Based on the simulation results, targets for future work are suggested in order to increase the efficiency of solar cells containing pyrite. The interpretive tools presented here may be applied to other photovoltaic materials as well. (C) 2002 Elsevier Science B.V. All rights reserved.