Solar energy is one of the primary sources of energy replacing fossil fuels due to its
abundance. Its versatility and environmental friendliness has made it one of the most promising
renewable sources of energy. Solar cells convert solar energy into Electrical Energy. The effort
to improve the efficiency of these cells and the reduction of their costs has been a major
concern for a long time. Modeling of various structures of solar cells provides an insight into
the physics involved in its operation and better understanding of the ways to improve their
efficiency. This work modeled Poisson Equation in 2D for an abrupt and linearly graded
charge densities system with arbitrary points in space. Linear approximation and differentials,
finite difference method, boundary conditions and MATLAB were used to obtain the solution.
This is the first step in developing a general purpose semiconductor device simulator that is
functional and modular in nature. It was observed that highest electric potential was obtained
where the point charge was placed for linearly graded and doping type changed over a small
distance compared to the extent of the depletion region for abrupt p-n junction. By solving
Poisson equation, voltage, electric field, electric charge density and density of free carriers
inside the solar cell can be known
