Dual Defect Passivation Engineering of Perovskite Photodetectors toward Infrared Filter-Free Full-Color Imaging

Abstract

Mainstream broadband photodetector-based full-color imaging systems rely on Bayer filters for spectral discrimination, which necessitates infrared cut filters to block near-infrared light—a process that inevitably reduces optical transmittance and increases system weight. Perovskite photodetectors offer a promising infrared-filter-free alternative due to their spectrally tunable characteristics, with blade-coating fabrication enabling large-area scalable production. However, intrinsic defects and environmental instability severely limit their practical implementation. To address these challenges, a synergistic strategy is proposed that effectively suppresses iodide oxidation through guanidinium ion doping and concurrently employs in situ passivation using pre-synthesized quasi-2D perovskites, collectively reducing defect-state density. The fabricated detector demonstrates key metrics toward full-frame perovskite photodetectors, achieving defect density at 1.66 × 10¹⁵ cm⁻³, specific detectivity at 1.42 × 10¹² Jones, and photoresponse nonuniformity of 1.21% across the active area. Systematic stability assessments further confirm outstanding environmental robustness; the ultimately fabricated large-area devices showed negligible change in switching characteristics after continuous operation for over 17 h and retained 90% of their initial EQE after 40 h under harsh conditions of 335.15 K and 80% relative humidity. Infrared-filter-free color imaging is demonstrated using a high-performance photodetector, validating its tremendous potential for full-color imaging applications.