CHARACTERIZATION OF THE I-V CURVES OF MULTI-JUNCTION SOLAR CELLS/MODULES BY HIGHFIDELITY SOLAR SIMULATORS AND THEIR IRRADIANCE DEPENDENCE

摘要

Procedure to characterize the performance of multi-junction solar cells and modules has been studied. Performance of the multi-junction devices is strongly affected by the balance of the photocurrent generated in each component cell. Especially, the total output current tends to be limited by the minimum photocurrent among the component cells, due to the requirement of current continuity. High-fidelity solar simulators, which incorporate Xe lamp(s) and halogen lamps, in order to simulate the AM1.5G standard sunlight including the water vapor absorption bands, have been employed for characterizing the multi-junction devices. It is shown that they can accurately reproduce the current generated in each component cells and the I-V curve of the devices under the standard sunlight, with simple spectral adjustment procedure, thanks to their basic good spectral fidelity to the standard sunlight. Irradiance dependence of the I-V curve is important for translating the I-V curve for different irradiance conditions. Although the translation is not straightforward for multi-junction devices, experimental results of the present study suggest that it is possible under practical spectral conditions.