In this paper we present the results of the simulation of interdigitated back contacts solar cell on thin-film (similar to 50 mu m) silicon layer. The influence of several parameters (surface recombination rate, substrate thickness and type, diffusion length, device geometry, doping levels) on device characteristics are simulated using the accurate two-dimensional numerical simulator DESSIS that allows to optimise the cell design. (c) 2004 Elsevier B.V. All rights reserved.