Ferroelectric-Empowered van der Waals Spectrometer with Record-High Sensitivity and Ultralow Noise

Miniaturized spectrometers are essential for portable and consumer-oriented applications, yet their reduced physical footprint inherently limits the detector’s active area, leading to compromised sensitivity. Conventional strategies to enhance sensitivity, such as cryogenic cooling or photomultiplier tubes, are incompatible with miniaturization due to their bulk, cost, and power demands. Here, we present a miniaturized spectrometer based on a van der Waals heterojunction integrated on a ferroelectric thin film. Spectral discrimination is enabled by engineering both interlayer and intralayer photoresponses within the heterojunction, which can be dynamically tuned solely via the source-drain bias, eliminating the need for a gate electrode and enabling a two-terminal architecture. This design is inherently compatible with simple two-pad readout integrated circuits, facilitating scalable array integration for compact spectroscopic systems. Critically, the built-in electric field generated by the ferroelectric polarization promotes efficient dissociation of interlayer excitons, yielding an ultralow noise floor of below 5 × 10–16 A Hz–1/2, more than 2 orders of magnitude lower than existing miniaturized spectrometers and surpassing the performance of most benchtop instruments. This work in sensitivity without sacrificing size or complexity present a strategy for deploying high-performance spectroscopy in real-world applications.