The Effect of Concentrated Light Intensity on Temperature Coefficient of the InGaP/InGaAs/Ge Triple-Junction Solar Cell

Research on automatic tracking solar concentrator photovoltaic systems has gained increasing focus in developing the solar PV technology. A paraboloidal concentrator with secondary optic is developed for a three-junction GaInP/GalnAs/Ge solar cell. The concentration ratio of this system is 200 and the photovoltaic cell is cooled by heat pipe. A detailed analysis on the temperature coefficient influence factors of triple-junction solar cell under different high concentration (75X,100X,125X,150X,175X and 200X) have been done based on the dish-style concentration photovoltaic system. The results show that under high concentrated light intensity, the temperature coefficient of Voc of triple-junction solar cell is increasing as the concentration ratio increased, from -10.84 mV/°C @ 75X growth to -4.73 mV/°C @ 200X. At low concentration, the temperature coefficient of Voc increases rapidly, and then increases slowly as the concentration ratio increased. The temperature dependence of η is increasing from -0.346%/°C @ 75X growth to -0.103%/°C @ 200X and the temperature dependence of Pmm and FF are increasing from -0.125 W/°C, -0.35%/°C @ 75X growth to 0.048W/°C, -0.076%/°C @ 200X respectively. It is indicated that the temperature coefficient of three-junction GaInP/GalnAs/Ge solar cell is better than that of crystalline silicon cell array under concentrating light intensity.