Electrically tunable two-dimensional heterojunctions for miniaturized near-infrared spectrometers

Miniaturized spectrometers are of considerable interest for their portability. Most designs to date employ a photodetector array with distinct spectral responses or require elaborated integration of micro & nano optic modules, typically with a centimeter-scale footprint. Here, we report a design of a micron-sized near-infrared ultra-miniaturized spectrometer based on two-dimensional van der Waals heterostructure (2D-vdWH). By introducing heavy metal atoms with delocalized electronic orbitals between 2D-vdWHs, we greatly enhance the interlayer coupling and realize electrically tunable infrared photoresponse (1.15 to 1.47 mu m). Combining the gate-tunable photoresponse and regression algorithm, we achieve spectral reconstruction and spectral imaging in a device with an active footprint < 10 mu m. Considering the ultra-small footprint and simple fabrication process, the 2D-vdWHs with designable bandgap energy and enhanced photoresponse offer an attractive solution for on-chip infrared spectroscopy. Miniaturized infrared spectrometers are required for imaging and remote sensing applications, but they are usually characterized by a cm-scale footprint. Here, the authors report the realization of near-infrared spectrometers based on Au-atom-intercalated ReS2/WSe2 heterostructures with an active footprint < 10 mu m and electrically tunable photoresponse.

Automated summary

This study presents the design of a super miniaturized near-infrared spectrometer based on two-dimensional vdWH, which achieves electrically tunable infrared photoresponse by introducing metal atoms. The design features a ultra-small device footprint and simple fabrication process, offering a promising solution for on-chip infrared spectroscopy.