Modelling and Analysis of Four-Junction Tendem Solar Cell in Different Environmenral Conditions

This paper present a MATLAB/Simulink model of a four junction tandem solar cell GaInP/GaAs/GaInAs/Ge for high efficiency. Tandem solar cell means it has more than one junction. The energy band gaps of the sub-cells in a GaInP/ GaAs/ InGaAs/ Ge 4-J tandem solar cell are 1.9 eV, 1.4 eV, 1.1eV and 0.75 eV respectively. In a space applications, generally triple junction from III-V compound semiconductor GaInP/GaAs/Ge is used, because it delivered highest efficiency compare to other commercially available triple junction solar cell. In a multi-junction solar cell, increasing the number of junctions generally offer higher efficiencies. We study here the mathematical model and electrical equivalent circuit of four layer multi-junction solar cell and compare with the triple junction and single junction solar cell and simulation of 4-layer multi-junction solar cell is discussed. We analyzed these models in various environmental conditions such as: solar irradiation, cell’s working temperature and concentration of suns. In this we consider three main factors: maximum power (Pmax), open circuit voltage, Short circuit current density of the solar cell. Taking into account the overall effect of solar irradiance and temperature, the model are evaluated, resulted simulated data are presented. It also include the effect on the bandgap of each sub-cells as well as diode reverse saturation current due to variation in the temperature.