Abstract
Multi-junction solar cells (MJSCs) are a current trend in the field of solar cells and form the backbone of concentrated photovoltaic systems. They are an attractive option because of their high efficiency, better power production and cost effectiveness. The aim of this paper is to present a general mathematical model of MJSC, suitable for computer simulation. This model investigates cell characterization curves including current density and power curves as a function of voltage for different concentration levels and number of junctions. The effect of varying material properties of junctions and tunneling layers is also analyzed. Two different types of MJSCs have been tested on the model, including InGaP–GaAs dual-junction solar cell with tunneling layer of InGaP and InGaP–GaAs–Ge triple-junction solar cell with tunneling layers of GaAs. Paper also presents the simulation results which are in agreement with practical conclusions.