Combining the higher energy yield of bifacial photovoltaic modules with the higher efficiency of silicon-based tandem devices is a promising pathway to reduce the levelized cost of electricity of photovoltaic systems. In a two-terminal bifacial tandem, the additional photon flux on the back of the bottom cell alters the current matching between the cells. This study quantifies this phenomenon, starting with spectrally resolved front and back irradiances determined from ray tracing under realistic conditions. A tandem-device model is then used to explore the impact of different scenarios on the optimal top-cell bandgap and power production. Although the energy gains from bifacial tandem systems are small, the range of suitable top-cell bandgaps is greatly broadened, thus widening the window of absorber candidates. In one exemplary case, a bifacial tandem with a top-cell bandgap as low as 1.63 eV retains the energy output of an optimized monofacial tandem with a 1.71-eV top cell.

将双面光伏模块的较高能量产量与硅基串联设备的较高效率相结合，是降低光伏系统电费平价化的有前途的途径。在两末端双向串联中，底部电池背面的附加光子通量会改变电池之间的电流匹配。这项研究从在现实条件下根据光线追踪确定的光谱分辨的前后辐照度开始量化了这种现象。然后，使用串联设备模型来探索不同方案对最佳顶部电池带隙和功率产生的影响。尽管从双面串联系统获得的能量很小，但是合适的顶部电池带隙的范围却大大拓宽了，因此拓宽了吸收体候选者的范围。在一种示例情况下，