Processing and Applications of Photodetectors Based on Hybrid Halide Perovskites and Their Heterostructures

ABSTRACT Halide perovskites have become leading candidates for next‐generation photodetectors because of their tunable bandgaps, strong light absorption, high carrier mobility, and compatibility with versatile fabrication methods. As the field has advanced, processing has emerged as a central factor governing the morphology, crystallinity, defect landscape, and interfacial quality of perovskite active layers, and therefore the final figures of merit of the device. This review examines the principal fabrication strategies used for perovskite photodetectors and their heterostructures, with particular emphasis on the relationship between processing route and device performance. Solution‐based methods such as spin coating, hot casting, spray coating, doctor blading, and inkjet printing are discussed alongside single‐crystal growth and hybrid‐integration approaches. Recent progress in solvent engineering, temperature control, gas‐assisted crystallization, and scalable deposition is analyzed in terms of its impact on film quality, charge transport, detectivity, responsivity, and response speed. This review also addresses the growing role of hybrid heterostructures based on perovskites combined with two‐dimensional materials and related functional layers for broadband and high‐sensitivity photodetection. By linking fabrication strategy with structural and optoelectronic outcomes, this review provides a critical perspective on current advances and remaining challenges toward reproducible, scalable, and application‐oriented perovskite photodetectors.