Hole Transport Layer‐Free Low‐Bandgap Perovskite Solar Cells for Efficient All‐Perovskite Tandems

of 0.911 V is realized, enabling all-perovskite TSCs with an efficiency of 26.03%. The taurine-based HTL-free TSCs have highly increased stability, retaining more than 90% and 80% of their initial PCEs after constant operation under 1-sun illumination for 600 h and under 55 °C thermal stress for 950 h, respectively. This work provides a facile strategy for fabricating efficient and stable perovskite devices with a simplified HTL-free architecture.