PRACTICAL SIMULATION OF THE I-V CURVE FOR AMORPHOUS-SILICON-BASED MULTIJUNCTION SOLAR-CELLS AFTER LIGHT SOAKING

A new procedure was developed to simulate the I-V curves of amorphous- silicon-based multijunction solar cells after light soaking. In the pr oposed method, the I-V curves of multi-junction cells were calculated by adjusting the measured I-V curves of component single-junction cell s, considering the effect of illumination-spectral dependence, using a newly developed formula for illumination-intensity dependence. Furthe rmore, during light soaking of single-junction cells, the light was so aked through proper optical filters which can reproduce almost the sam e spectrum and intensity of incident Light under the multijunction con dition. Consequently, the I-V curves estimated by this method agreed v ery well with measured values for real multijunction cells not only be fore but also after Light soaking. A high stabilized conversion effici ency of 10.6% for an a-Si/a-SiGe 2-stack solar cell has been achieved, for which the efficiency estimated using this method Ras 10.7%.