Modeling and simulation of the influence of quantum dots density on solar cell properties

Based on the finite element method using the FEniCS computing platform and python programming, we solve the Schrödinger equation within the effective mass approximation. Its solution gives us the necessary energy for an electron to transit from an intermediate band to a conduction band, as well as the distribution of probability density within the system. In this work, we have investigated the efficiency of the InAs/GaAs pyramid quantum dot intermediate band solar cell (PQD-IBSC) as a function of the structure parameters and quantum dot density. The simulation results indicated the strong dependence of the efficiency of PQD-IBSC on the confinement effect, quantum dot number or quantum dot density and coupling strength. The conversion efficiency grows from 14.4587% to the optimal efficiency 17.8807%. Generally, the best efficiency is obtained for small barrier width, large quantum dot height and great quantum dot density.