Scalable Graphene/Sn-WSe₂/Si Photodetector Array With Broadband Response and Starlight Sensitivity for All-Light...

The development of photodetectors that match the sensitivity of biological vision while extending the response beyond the visible spectrum remains a key challenge. Here, we report a scalable photodetector array based on graphene/amorphous Sn-doped WSe₂/Si (Gr/Sn-WSe₂/Si) heterostructures. The pulsed-laser-deposited Sn-WSe₂ nanofilm exhibits a long carrier lifetime (>5.5 ns). Combined with efficient photocarrier separation in a stacked heterostructure, it enables a remarkable self-powered photoresponse from 365 to 1550 nm. The device achieves a low noise-equivalent power of 0.029 fW/Hz^1/2 and a specific detectivity of 3.4 × 10¹⁴ Jones at 808 nm, exceeding retinal sensitivity while offering a broader spectrum. It also boasts a high photo-switching ratio > 10⁶ and fast rise/decay times of 18.3/27.2 µs. Capitalizing on these attributes, broadband visualization, see-through imaging, and starlight-level perception at 0.88 nW/cm² are demonstrated. Moreover, the photodetector array exhibits excellent pixel-to-pixel uniformity, paving the way for the practical deployment of next-generation imaging technology.