SIMULATION OF HETEROJUNCTION SOLAR CELL AND ANALYSIS OF IT BY VARYING DIFFERENT PARAMETERS

Abstract

In this thesis, simulation of heterojunction solar cell has been carried out and it has been demonstrated how different parameter variations such as width, relaxation time and beam affect its performance in terms of efficiency and spectral response. A virtual wafer fabrication tool (VWFT), Silvaco ATLAS has been used for analysis of three layer InGaP/GaAs/Ge solar cell to obtain a high efficiency solar cell. Initially, width is varied, then on a definite width relaxation time has been changed and with each variation, different parameters of solar cell has been obtained via Silvaco ATLAS and corresponding I-V curve has been plotted. The author chose to vary these parameters as on variation of these parameters, the efficiency is improved, photogeneration rate ameliorated and so, current and power also increases. Taun and Taup are relaxation time of electrons and holes respectively. When relaxation time is increased, time for electrons and holes to recombine also increases and therefore, electrons and holes contribute more to current, current density and short circuit voltage. This, thus, results in an increase in the fill factor, power and efficiency. As the intensity of Sun increases, the number of photons falling per unit surface area of solar cell increases, thus creating a lot of holes and electrons which increases the current and voltage leading to an increase in the fill factor, power and efficiency. Further, the impact of width has been studied on the solar cell performance.