Modeling High-Efficiency Rear Junction Photovoltaic Devices

Solar cells are a renewable energy technology that has begun to supply energy in many regions of the world at a utility scale. Nonetheless, further improvements in solar technology are still needed to help reduce costs and increase adoption. Many researchers have been particularly interested in demonstrating higher efficiencies through new materials and designs. Some of the most efficient technologies are made from III-V materials, which feature strong absorption and radiative recombination. Rear junction III-V solar cell devices are of particular interest, as they have been proven to provide higher efficiencies compared to traditionally structured devices. This is believed to be caused by reduced bulk recombination and enhanced photon recycling. However, their performance is not fully understood at this time. In particular, previous studies produced a discrepancy between previous simulated literature and experimental fitted values, at odds with prior independent measurements of the material properties. To help develop a better understanding of these cells, we have developed a tool to examine the parameters that properly fit experimental data sets. Our tool features a web-enabled graphical user interface that allows the user to set the range of parameters to sweep. It then outputs contour plots to determine which ranges of values are most consistent with experimental results. This simulation tool will provide a more accurate understanding of the behavior of GaInP rear-junction solar cells, and more generally, will help advance our understanding of how unconventional solar cell architectures and materials can help achieve higher efficiencies. Future benefits may include improved design techniques for single-junction photovoltaics for terrestrial use, as well as multi-junction high-performance cells for aerospace applications