In metal halide perovskite solar cells the formation of a 2D/3D bulk heterostructure has a positive effect on device stability but can be detrimental to charge transport and power conversion efficiency (PCE). Herein, we report that amidino-based Dion-Jacobson 2D perovskite enables the creation of an efficient and stable FAPbI₃-based 2D/3D heterostructure in perovskite solar cells. The 2D-perovskite-assisted nucleation/growth of 3D perovskites during film formation was found by using time-resolved optical diagnostics, which decrease concentrations of voids and bulk defects of perovskite films for efficient charge transport. The planar perovskite solar cells based on 2D/3D heterostructures achieved efficiencies of 24.9% and 22.3% on rigid and flexible substrates, respectively, which are the highest efficiencies among all 2D/3D composite solar cells. Improved stability was further demonstrated, with 97% of original efficiency retained for rigid solar cells without encapsulation after 1,000 h of storage under ambient conditions (RH 30%–40%) and 92% for flexible solar cells after 3,000 bending cycles.

在金属卤化物钙钛矿太阳能电池中，2D/3D 体异质结构的形成对器件稳定性有积极影响，但可能不利于电荷传输和功率转换效率 (PCE)。在此，我们报道基于脒基的 Dion-Jacobson 2D 钙钛矿能够创建高效稳定的 FAPbI ₃钙钛矿太阳能电池中基于 2D/3D 异质结构。通过使用时间分辨光学诊断，发现了薄膜形成过程中 2D 钙钛矿辅助的 3D 钙钛矿成核/生长，这降低了钙钛矿薄膜的空隙和体积缺陷的浓度，以实现有效的电荷传输。基于2D/3D异质结构的平面钙钛矿太阳能电池在刚性和柔性基板上的效率分别为24.9%和22.3%，是所有2D/3D复合太阳能电池中效率最高的。进一步证明稳定性得到改善，在环境条件下（RH 30%–40%）储存 1,000 小时后，未封装的刚性太阳能电池保持 97% 的原始效率，在 3,000 次弯曲循环后，柔性太阳能电池保持 92% 的原始效率。