Bilayer interface engineering through 2D/3D perovskite and surface dipole for inverted perovskite solar modules
Jiarong Wang, Leyu Bi, Xiaofeng Huang, Qifan Feng, Ming Liu, Mingqian Chen, Yidan An, Wenlin Jiang, Francis Lin, Qiang Fu, Alex K.‐Y. Jen
Abstract
The persistency of passivation and scalable uniformity are vital issues that limit the improvement of performance and stability of large-area perovskite solar modules (PSMs). Here, we design a bilayer interface engineering strategy that takes advantage of the stability and passivation ability of low-dimensional perovskite and the dipole layer. Introducing phenethylammonium iodide (PEAI) can form 2D/3D heterojunctions on the perovskite surface and effectively passivate defects of perovskite film. Interestingly, the upper piperazinium iodide (PI) layer can still form surface dipoles on the 2D/3D perovskite surface to optimize energy-level alignment. Moreover, the bilayer interface engineering enables large-area perovskite films with uniform surface morphology, lower trap-state density and stability against environmental stress factors. The final devices achieved a small-area PCE of 25.20% and a large-area (1 cm<sup>2</sup>) PCE of 23.96%. A perovskite mini-module (5 × 5 cm<sup>2</sup> with an active area of 14.28 cm<sup>2</sup>) could also be fabricated to achieve a PCE of 23.19%, ranking it among the highest for inverted PSMs. Additionally, the device could retain over 93% of its initial efficiency after MPP tracking at 45 °C for 1280 h. This study successfully demonstrates a bilayer interface engineering with respective functions, offering valuable insights for producing efficient and stable large-area PSCs. © 2024 The Authors