SnSe/SiO2/Si Heterostructures for Ultrahigh-Sensitivity and Broadband Optical Position Sensitive Detectors

In this letter, optical position sensitive detectors (PSDs) based on SnSe/SiO2/Si heterostructures with an atomically abrupt interface are fabricated via the van der Waals (vdWs) growth of the large-area multilayered SnSe nanosheets on SiO2-buffered Si. The as-fabricated SnSe/SiO2/Si PSD device has a broadband photoresponse from visible to near-infrared light, especially showing an extremely high sensitivity up to 687.5 mV/mm under a relatively low laser power of 1.0 mW. The unique characteristics from the SnSe/Si vdWs interface are proposed to be the key factors to contribute to the excellent performance.