This work is devoted to the modeling and simulation of quantum dot solar cells (CSBQs) based on InAs/GaAs by the finite element method (MEF) with the FreeFem++ software. It analyzes the performance of these cells by studying the influence of certain parameters such as geometric parameters, the number, mole fraction and size of the elements constituting the InAs quantum nanostructure, and also the effect of certain physical parameters such as the lifetime of minority carriers and the surface recombination speed to optimize the efficiency of photovoltaic conversion. This book consists of two parts: the first deals with the principle of calculation of the finite element method, and the implementation of the FreeFem++ software are also covered the construction of nodal equations as well as the assembly technique characteristics of the numerical implementation of the finite element method. In the second part, the principle of photoelectric conversion by the third generation of photovoltaic cells based on III-V semiconductors was analyzed.