Chalcogen Alloy‐Engineered Te 2 Se/Si Heterojunctions for Low‐Noise Complementary Metal‐Oxide Semiconductor‐Compatible Short‐Wave Infrared Imaging

ABSTRACT Developing complementary metal‐oxide semiconductor (CMOS)‐compatible and scalable short‐wave infrared (SWIR) photodetectors remains challenging owing to the high costs and integration limits of conventional indium gallium arsenide and mercury cadmium telluride technologies. Here, we report a chalcogen alloy design strategy for Te 2 Se/Si heterojunction photodetectors using atomistic simulations to suppress oxygen‐related trap formation. CMOS‐compatible Te 2 Se/n‐Si photodetectors fabricated by radio‐frequency magnetron co‐sputtering exhibit superior performance compared with Te/n‐Si counterparts. Structural and optical analyses confirm Se‐induced bandgap widening to 0.62 eV and reduced carrier concentration (∼10 17 cm −3 ), resulting in a rectification ratio of approximately 4.0 × 10 6 , a two‐orders‐of‐magnitude reduction in reverse dark current, and an extended SWIR photoresponse. The Te 2 Se/n‐Si photodetector also exhibits over three orders of magnitude lower current noise density, a specific detectivity of approximately 4.49 × 10 10 Jones at 1300 nm, and a sub‐millisecond photoresponse. Finally, a PCB‐integrated 14 × 14 imaging array demonstrates high‐contrast SWIR imaging, highlighting the potential of Te 2 Se/Si heterojunctions as a CMOS‐compatible, scalable, and low‐noise SWIR photodetection platform.