N,N-dimethyl-2-aminosulfonyl nicotinamide additive engineering for high-performance wide-bandgap perovskite solar cells

The quality of the perovskite active layer is pivotal to realizing high power conversion efficiency (PCE) and long-term durability in perovskite solar cells (PSCs). Specifically, lattice mismatch-induced inhomogeneities in low-quality perovskite films give rise to considerable residual strain, which poses a severe barrier to the practical application of high-performance photovoltaic devices. In this research, we propose the incorporation of N,N-dimethyl-2-aminosulfonyl nicotinamide (C₈H₁₁N₃S, hereafter referred to as ANdPy) as an additive into the perovskite film. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy measurements demonstrate that the proposed additive binds to uncoordinated Pb²⁺ ions via carbonyl groups, sulfonyl groups, and passivated iodine (I) atom defects, thereby enhancing carrier dynamics and mitigating residual stress within the perovskite film. Consequently, the ANdPy-modified inverted wide-bandgap PSCs achieves a champion PCE of 18.52% and a high fill factor of 81.80%. Moreover, the ANdPy-modified device exhibits improved photo and thermal stability. This study proposes a reliable strategy for mitigating residual stress in perovskite films through additive engineering, thereby offering valuable support for promoting the commercialization of PSCs.