Scaling Short-Wave Infrared Detector Pixels to Subwavelength Dimensions

Pixel miniaturization is crucial for advancing high-resolution short-wave infrared (SWIR) imaging, particularly for remote sensing, consumer electronics, and portable platforms. However, conventional epitaxial photodiode technologies have been limited to approximately 10 µm pixels, and systematic investigations of pixel miniaturization limits in SWIR detection are lacking. Here, we report the pixel scaling behavior of carbon nanotube (CNT) film heterojunction-gated field-effect transistor (HGFET) detectors and demonstrate the feasibility and performance improvement of subwavelength pixel SWIR detectors. Specifically, the main performance indicators of the HGFET detectors consistently improve, particularly the specific detectivity and response speed as the pixel is scaled from 5.5 to 1.0 µm. A HGFET detector with a subwavelength pitch of 0.65λ (∼1.0 µm) has a record specific detectivity exceeding 10¹⁵ cm·Hz^1/2·W^-1 at 1300 nm and rise/fall times of 132/148 µs. Through their compatibility with silicon-based readout circuits, submicron-pixel CNT HGFET arrays offer scalable and cost-effective platforms for next-generation high-resolution SWIR imaging systems.