High‐Performance Broadband Infrared Photodetector Based on a VOPc/1T'‐MoTe 2 /Ultra‐Thin SiO 2 /Si Double Heterojunction

ABSTRACT Silicon‐based photodetectors integrated with two‐dimensional (2D) materials are promising for broadband photodetection, yet simultaneously achieving high responsivity, fast response, and broadband near‐infrared (NIR) detection remains challenging. Herein, we demonstrate a high‐performance broadband photodetector based on a VOPc/1T'‐MoTe 2 /ultra‐thin SiO 2 /Si double‐heterojunction. Density functional theory calculations reveal additional electronic states near the Fermi level in the VOPc/1T'‐MoTe 2 heterostructure, providing electronic channels for sub‐bandgap photoexcitation. VOPc enhances optical absorption and strengthens the built‐in electric field, facilitating photocarrier separation, transfer, and collection while suppressing recombination. The device exhibits a broad photoresponse from 375 to 1550 nm. Under 808 nm illumination, it achieves a responsivity of 0.85 A/W, detectivity of 1.67 × 10^9 Jones, and fast rise/fall times of 26.77/15.27 µs, significantly outperforming the corresponding 1T'‐MoTe 2 /ultra‐thin SiO 2 /Si device. The enhanced broadband response originates from synergistic improvements in light harvesting, interfacial electric fields, and carrier transport across the VOPc/1T'‐MoTe 2 interface. This work demonstrates an effective strategy for silicon‐compatible broadband photodetectors by integrating 2D semimetals with organic semiconductors.