In-homogeneous luminescent coupling of multi-junction solar cell under non-uniform irradiation and temperature distribution

The luminescent coupling effect in practical multi-junction solar cell is spatially in-homogeneous even under uniform irradiation and temperature distribution. The spacial inhomogeneity of luminescent coupling is modeled and simulated under various scenarios. Quasi 3-D equivalent model of tandem solar cell is extended to adapt to temperature dependent luminescent coupling. Vertical current of each region of the cell is dominated by temperature or irradiation. Besides, luminescent coupling current of each subcell pair is mainly regulated by surface voltage profile of the cell. Front grids, busbars and lateral resistance have great impact on luminescent coupling current. Non-uniform irradiation only affects the shape of contour lines, but the overall trend of luminescent coupling current profile remains unchanged. Moreover, when temperature distribution variance is large, some areas of the photovoltaic cell will reverse bias and convert to a load, which leads to a rather irregular distribution of luminescent coupling current.