Dipole interface engineering in perovskite solar cells: Mechanisms, design, and application advances

The commercialization of perovskite solar cells (PSCs) is hindered by critical interfacial challenges, including energy level mismatch, defect-induced non-radiative recombination, and environmental instability. Interfacial dipole engineering, which introduces a directional dipole field between the perovskite and transport layers, has emerged as an effective strategy to synergistically enhance device performance and stability. This review systematically summarizes the recent significant advances in this field. First, it examines how dipole layers function to optimize energy level alignment, passivate surface defects, and enhance environmental robustness. Next, from a molecular‑engineering perspective, the review outlines design principles and structure-property relationships of dipole molecules, highlighting their applications in different device architectures. Finally, this paper discusses the current challenges and future directions in this field, as dipole interface engineering is emerging as one of the key technologies driving the industrialization of perovskite optoelectronic devices.