Tandem devices combining perovskite and silicon solar cells are promising candidates to achieve power conversion efficiencies above 30% at reasonable costs. State-of-the-art monolithic two-terminal perovskite/silicon tandem devices have so far featured silicon bottom cells that are polished on their front side to be compatible with the perovskite fabrication process. This concession leads to higher potential production costs, higher reflection losses and non-ideal light trapping. To tackle this issue, we developed a top cell deposition process that achieves the conformal growth of multiple compounds with controlled optoelectronic properties directly on the micrometre-sized pyramids of textured monocrystalline silicon. Tandem devices featuring a silicon heterojunction cell and a nanocrystalline silicon recombination junction demonstrate a certified steady-state efficiency of 25.2%. Our optical design yields a current density of 19.5 mA cm⁻² thanks to the silicon pyramidal texture and suggests a path for the realization of 30% monolithic perovskite/silicon tandem devices.

结合钙钛矿和硅太阳能电池的串列器件有望以合理的成本实现30％以上的功率转换效率。迄今为止，最先进的整体式两端子钙钛矿/硅串联装置具有硅底部电池的特征，该硅底部电池在其正面进行了抛光以与钙钛矿的制造工艺兼容。这种让步导致更高的潜在生产成本，更高的反射损耗和不理想的光陷获。为了解决这个问题，我们开发了一种顶层电池沉积工艺，该工艺可以在具有纹理的单晶硅的微米级金字塔上直接实现具有受控光电特性的多种化合物的共形生长。具有硅异质结电池和纳米晶硅复合结的串联器件证明经验证的稳态效率为25.2％。我们的光学设计可产生19.5 mA cm的电流密度^{− 2}得益于硅金字塔形纹理，为实现30％整体钙钛矿/硅串联器件的实现提供了一条途径。