We have applied Rosenbrock's optimization algorithm to obtain the optimized efficiency of a solar cell and its structural parameters. To obtain these parameters. we have developed a computer pro-ram for simultaneous optimization and simulation of the solar cell. We have used experimental data on the electrical and optical properties of a-Si(1-x)C(x) layers, put them into the written code and obtained the optimized parameters of this solar cell. The maximum efficiency is 6.32% which is close to one experimental result. (C) 2004 Elsevier B.V. All rights reserved.