Constructing 3D/2D perovskite heterostructures for boosting photodetection performance

Following the unprecedented improvements in photovoltaic power conversion efficiencies, 3D/2D perovskite heterostructures have emerged as a powerful platform for high-performance perovskite photodetectors by leveraging complementary physicochemical properties. Their key advantage lies in synergistic interfacial band engineering, which integrated the strong light absorption of 3D perovskites with the spectral tunability and enhanced environmental stability of 2D counterparts, while improving charge-carrier transport efficiency. This synergy enables simultaneous optimization of key photodetector performance metrics, including detectivity, response speed, and operational stability. However, achieving precise, scalable, and cost-effective control over interfacial phase purity and crystallographic orientation remains a major challenge for commercialization. This review critically summarizes recent advances in interfacial engineering strategies for 3D/2D perovskite photodetectors. We first introduce the fundamentals and key performance parameters of photodetectors, followed by an overview of the advantages of perovskites as active materials. We then discuss both the theoretical and experimental advantages of 3D/2D heterostructures relative to single-phase 3D and 2D perovskites. Furthermore, we examine the main fabrication methods and analyze how heterointerface optimization enhances device performance. Finally, the remaining challenges and future directions toward high-performance, stable, and scalable 3D/2D perovskite photodetectors are outlined.