Dynamically Hardware‐Level Encryption Based on PbSe Quantum Dots‐Modulated 2D Heterostructure Photodetector

With the emergent demand for secure communication technologies, photodetectors that integrate high‐performance broadband detection with encryption functionalities are vital to address the escalating cybersecurity challenges. Here, we present a device‐level embedded encryption approach via dynamically engineering the energy barrier at the van der Waals heterointerface through quantum dots (QDs) integration. Incorporating PbSe QDs into the MoTe 2 /MoSe 2 heterostructure introduces a bias‐reconfigurable interfacial barrier, enabling multiple photoresponse states under dual‐voltage (drain‐source, V ds , and gate‐source, V gs ) modulations. Driven by dual‐voltage‐controlled band bending, the device exhibits encrypted photocurrents with well‐distinguished states, thereby enabling the implementation of a physical‐layer cryptographic protocol. This synergy supports the device's real‐time encryption key generation through voltage‐driven carrier dynamics. The dual‐channel encryption capability allows independent data streams to be securely transmitted via V ds and V gs encoding with an ultralow estimated theoretical bit error rate, where eavesdropping is inherently thwarted by nonlinear photocurrent‐state dependencies. Additionally, the integration of PbSe QDs into the heterostructure simultaneously delivers enhanced broadband photodetection performance from 532 to 2200 nm, achieving a notable responsivity of 80 A W −1 at 1550 nm. Our work bridges high‐performance photodetection with data encryption, offering an innovative route for future advancements in optoelectronics and secure communication systems.