Buried Interface Engineering Enables Efficient, Scalable, and Stable Inverted Perovskite Solar Cells

Poly[bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine] (PTAA), as an extensively used hole transport material in inverted perovskite solar cells (PSCs), has given reason for concern due to its hydrophobicity for a long time. Herein, buried interface engineering is applied for the scalable deposition of perovskite films by introducing an amphiphilic molecule hexadecyltrimethylammonium chloride on the PTAA surface, which improves the interfacial wettability of the perovskite precursor solution on the organic hole transport layer (HTL), facilitates the nucleation and growth of perovskites, and reduces the nonradiative recombination at the perovskite/HTL interface. As a result, all photovoltaic parameters of the inverted PSCs are improved significantly. The champion devices demonstrate power conversion efficiencies (PCEs) of 22.04% and 20.47% with aperture areas of 0.148 and 1.0 cm 2 , respectively. Moreover, the encapsulated 1.0 cm 2 device exhibits excellent stability and maintains over 70% of its initial PCE after 1200 h under continuous 1 sun illumination at 65 °C in a nitrogen environment.