High-phase purity two-dimensional perovskites with 17.3% efficiency enabled by interface engineering of hole transport layer
Siraj Sidhik, Yafei Wang, Wenbin Li, Hao Zhang, Xinjue Zhong, Ayush Agrawal, Ido Hadar, Ioannis Spanopoulos, Anamika Mishra, Boubacar Traoré, Mohammad H. K. Samani, Claudine Katan, Amanda B. Marciel, Jean‐Christophe Blancon, Jacky Even, Antoine Kahn, Mercouri G. Kanatzidis, Aditya D. Mohite
Abstract
State-of-the-art p-i-n-based 3D perovskite solar cells (PSCs) use nickel oxide (NiOX) as an efficient hole transport layer (HTL), achieving efficiencies >22%. However, translating this to phase-pure 2D perovskites has been unsuccessful. Here, we report 2D phase-pure Ruddlesden-Popper BA2MA3Pb4I13 perovskites with 17.3% efficiency enabled by doping the NiOX with Li. Our results show that progressively increasing the doping concentration transforms the photoresistor behavior to a typical diode curve, with an increase in the average efficiency from 2.53% to 16.03% with a high open-circuit voltage of 1.22 V. Analysis reveals that Li doping of NiOX significantly improves the morphology, crystallinity, and orientation of 2D perovskite films and also affords a superior band alignment, facilitating efficient charge extraction. Finally, we demonstrate that 2D PSCs with Li-doped NiOX exhibit excellent photostability, with T99 = 400 h at 1 sun and T90 of 100 h at 5 suns measured at relative humidity of 60% ± 5% without the need for external thermal management.