Self-Powered and High-Sensitivity 2D Perovskite/InSe Heterostructure Waveguide Photodetector for On-Chip Visible-Light Biosensing

Visible-light photonic integrated circuits (PICs) with self-powered and high-sensitivity waveguide photodetectors (PDs) are essential for advancing next-generation biosensing, optogenetics, and DNA sequencing technologies. Conventional bulk-material-based visible PDs integrated on silicon nitride (SiN) platforms have limitations, including complex fabrication, lattice mismatch, and the need for high bias voltages in avalanche detection, which hinder low-cost manufacturing and energy-efficient scalability. Here, we present a self-powered 2D perovskite/InSe van der Waals (vdWs) heterostructure waveguide PD integrated onto a SiN photonic platform for on-chip visible-light biosensing. Leveraging the strong light-matter interaction of 2D perovskite and the built-in electric field at the perovskite/InSe interface, the device achieves an ultralow dark current of 2.6 × 10–13 A at zero bias and exceptional sensitivities, with normalized photocurrent-to-dark-current ratios (NPDRs) of up to 5.0 × 107 mW–1. The PD exhibits fast temporal response (∼20 ms) and excellent self-powered operation, enabling energy-efficient visible-light detection. We further demonstrate visible SiN slot waveguides monolithically integrated with 2D vdWs PDs for fluorescence-labeled DNA detection, yielding a sensitivity of 30.6 pA μM–1 and a detection limit of 100 nM at zero bias. Our results establish a scalable route to energy-saving, high-performance visible-light biosensing PICs based on 2D vdWs heterostructure PDs.