Perovskite solar cells are used in silicon-based tandem solar cells due to their tunable band gap, high absorption coefficient and low preparation cost. However, the relatively large optical refractive index of bottom silicon, in comparison with that of top perovskite absorber layers, results in significant reflection losses in two-terminal devices. Therefore, light management is crucial to improve photocurrent absorption in the Si bottom cell. In this paper, nanoholes array filled with TiO₂ is introduced into bottom cells design. By finite-difference time-domain methods, the absorption efficiency and photocurrent density in the range of 300–1100 nm has been analyzed, and the structural parameters have been also optimized. Our calculations show the photocurrent density which tends to be saturated with the increase in the height of the nanoholes. The absorption enhancement modes of photons at different wavelengths have been analyzed intuitively by the distribution of electric field. These results enable a viable and convenient route toward high efficiency design of perovskite/Si tandem solar cells.

钙钛矿太阳能电池因其可调节的带隙，高吸收系数和低制备成本而用于硅基串联太阳能电池。然而，与顶部钙钛矿吸收层相比，底部硅的相对较大的光学折射率导致在两个端子装置中的显着反射损耗。因此，光管理对于提高硅底部电池的光电流吸收至关重要。在本文中，纳米孔阵列填充了TiO ₂被引入到底部单元格设计中。通过时域有限差分法，分析了300-1100 nm范围内的吸收效率和光电流密度，并优化了结构参数。我们的计算表明，随着纳米孔高度的增加，光电流密度趋于饱和。通过电场分布直观地分析了不同波长的光子的吸收增强模式。这些结果为钙钛矿/硅串联太阳能电池的高效设计提供了一条可行且方便的途径。