High Sensitive and Broadband Photodetectors Based on Hybrid PbI₂ Nanosheet/CdSe Nanobelt

Abstract The limited detection of lead iodide (PbI₂) to visible light hinders the further development of PbI₂ in the field of optoelectronic applications. A photodetector based on PbI₂ nanosheet/CdSe nanobelt (PbI₂ NS/CdSe NB) is prepared for the first time. This composite structure exhibits broadband spectral photoresponse from ultraviolet (400 nm) to red (730 nm). More importantly, PbI₂ NS/CdSe NB can promote the effective separation of electron–hole pairs and improve the photoelectric performance. Compared to single PbI₂ NS, the PbI₂ NS/CdSe NB photodetector exhibits higher light–dark current ratio (6.778 × 10³ A), responsivity (347.57 A W⁻¹), and detectivity (3.625 × 10¹⁵ Jones) under 490 nm illumination. A new strategy is provided here to design broadband and high‐performance photodetectors.