Giant Light‐Heat‐Electricity Conversion in Photothermoelectric Detector Enabled by Semiconductor‐Dielectric Superlattices

ABSTRACT

Photothermoelectric (PTE) detectors, which operate relying on the photothermal and thermoelectric effects, can overcome the intrinsic spectral limitations originated from material bandgaps in photon‐driven detectors. However, the hardware implementation of devices leveraging light‐heat‐electricity cascade conversion remains challenging. Here, we report the construction of MoS ₂ /SiO ₂ semiconductor/dielectric superlattice films with features of nanoscale layer definition, high crystalline quality, and wafer‐level manufacturability. Benefiting from the interlayer interference and electric‐field localization, the MoS ₂ /SiO ₂ superlattices exhibit remarkably enhanced optical absorption across the visible to infrared spectrum, which enables the high photothermal energy conversion efficiency and substantial temperature rise exceeding 70 K. The PTE detection, implemented by integrating superlattice absorber with a microscale thermoelectric (μ‐TE) platform based on Bi ₂ Te ₃ /Sb ₂ Te ₃ P–N pairs, enables high‐efficiency photodetection through strong light–matter interaction and optimized thermal management. The self‐powered detector can stably operate over a broad‐spectrum range extending to 1550 nm, demonstrating a temporal response (∼16 ms), high responsivity (17.6 V W ⁻¹ ), and detectivity exceeding 1.20 × 10 ¹⁰ Jones, comparable to state‐of‐the‐art broadband PTE detectors. Array‐level integration facilitates high‐fidelity 1550 nm imaging with a 256‐pixel prototype, while wafer‐scale fabrication of over 3000 units on a 2‐inch substrate confirms excellent uniformity, reproducibility and scalability, unlocking the potential for advanced large‐scale imaging applications.