Abstract
2D Ruddlesden–Popper (2DRP) perovskites with hydrophobic bulky cations are proven to improve the environmental stability in photovoltaic devices significantly. However, these spacer cations lead to a weak interplay in the 2DRP perovskites, severely impacting the charge carrier transport and require a systematic understanding of the interaction between spacer cations and inorganic slabs. Herein, a series of novel perovskites (BA1−xNMAx)2MA3Pb4I13 (NMA = 1‐naphthalenemethylammonium, BA = n‐butylammonium) are successfully fabricated to reveal the interaction of mixed spacers and inorganic slabs. Incorporating NMA cations enhances the NH⋯I− hydrogen‐bonding interaction between the spacer cations and [PbI6]4− slabs, resulting in a preferentially crystal vertical orientation of smoothed perovskite films with larger crystal grains. Thus, a significant reduction in the density of trap states of the resulting 2DRP perovskites is achieved which leads to highly efficient charge carrier transport. Consequently, the champion (BA0.9NMA0.1)2MA3Pb4I13 device yields a power conversion efficiency (PCE) of 14.21%, along with the unencapsulated devices that can retain 85% of their initial PCE for 1200 h under 35–65% relative humidity conditions. This work provides a simple and original method to modulate the interlayer interplay in 2DRP perovskites for highly efficient and air‐stable perovskite solar cells.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have