Data on the design optimization, indoor characterization and outdoor testing of GaAs/Bifacial Si heterojunction four-terminal photovoltaic systems

The development of a highly efficient multijunction technology is a key challenge for the future of photovoltaic and for the transition to more renewable energy sources. In this scenario, four-terminal architecture (4T) compared to the classic tandem design allows a large intrinsic robustness to the variations of the solar spectrum, which continuously occur under normal outdoor operation conditions. On the other hand, bifacial solar cells and modules have already proven to be able to increase the energy yield of solar farms at reduced costs. For these reasons, a thorough investigation of the compatibility between these two solutions has been performed by combining a III-V semiconductor with the silicon heterojunction technology in a four-terminal device. This work has been designed in support of the research article entitled “Outdoor performance of GaAs/Bifacial Si Heterojunction four-terminal system using optical spectrum splitting” [1], which showed, through data modeling and an accurate daily analysis of the spectral distribution of solar light, how a four-terminal architecture guarantees the consistency of the bifacial gain and more robust performances than a two-terminal system. Here additional data on the manufacturing, optimization and characterization of the device are presented.