An alternative arrangement to triple-junction devices for reduced temperature effect and enhanced spectrum coverage

The performance of triple-junction photovoltaic (PV) devices depends on the distribution of their energy bandgaps, the concentration ratio and operational temperature. The choice of materials for such devices is based on trading the optimum bandgap for the lattice parameter. Also, the sub-cells behave differently under light concentration and having them operating together under the same concentration may be another compromise on the overall performance. Furthermore, these devices are designed to operate under high concentration, and this results in having them functioning at high temperatures. In this work, we tackle these issues by proposing an alternative arrangement to triple-junction devices. We propose that the sun-beam is split by an optical filter and one part of the solar spectrum goes towards a single-junction AlGaAs cell while the other part is directed towards a double-junction cell where five different bandgap combinations are considered. In this work a simulation model is built to investigate the mutual effect of bandgap combination, light concentration and operational temperature on the overall performance of the alternative arrangement. The paper also compares these performance improvements with the optical losses associated with beam splitting.