Numerical Simulation and Experimental Analysis of Electrical Properties of InGaP/InGaAs/Ge Triple-Junction Solar Cell with Reflective High-Concentration Photovoltaic System

Abstract

Photovoltaic power systems is one of the most important ways of utilizing solar energy, and high-concentration photovoltaic systems have received much attention due to its high conversion efficiency. This study developed a mathematical model of an InGaP/InGaAs/Ge triple-junction solar cell (TJSC) according to a single-diode equivalent circuit. Moreover, a correlation of the series resistance of TJSC considering the effects of temperature and incident energy density was obtained and further verified by experiments. Based on a reflective high-concentration photovoltaic system, the electrical properties, including the short-circuit current, open-circuit voltage, peak power, and efficiency, were investigated. The results showed that the series resistance increased from 0.0095 Ω to 0.0123 Ω with temperature increased from 298 K to 358 K at the incident of 2×105 W /m2, and it increased from 0.0094 Ω to 0.0196 Ω as the incident energy density increased from 2.0×105 W/m2 to 1.0×106 W/m2 at temperature of 298K. In addition, the relationships between other electrical properties and the incident energy density or temperature were investigated. The simulations were remarkably consistent with the experimental results. The experimental values were slightly less than the theoretical values, which was caused mainly by the temperature instead of the incident energy density.