Fabrication of 1D Te/2D ReS₂ Mixed-Dimensional van der Waals <i>p-n</i> Heterojunction for High-Performance Phototransistor.

Abstract

The superior optical and electronic properties of the two-dimensional (2D) rhenium disulfide (ReS₂) makes it suitable for nanoelectronic and optoelectronic applications. However, the internal defects coupled with with the low mobility and light-absorbing capability of ReS₂ impede its utilization in high-performance photodetectors. Fabrication of mixed-dimensional heterojunctions is an alternative method for designing high-performance hybrid photodetectors. This study proposes a mixed-dimensional van der Waals (vdW) heterojunction photodetector, containing high-performance one-dimensional (1D) <i>p</i>-type tellurium (Te) and 2D <i>n</i>-type ReS₂, developed by depositing Te nanowires on ReS₂ nanoflake using the dry transfer method. It can improve the injection and separation efficiency of photoexcited electron-hole pairs due to the type II <i>p-n</i> heterojunction formed at the ReS₂ and Te interface. The proposed heterojunction device is sensitive to visible-light sensitivity (632 nm) with an ultrafast photoresponse (5 ms), high responsivity (180 A/W), and specific detectivity (10⁹), which is superior to the pristine Te and ReS₂ photodetectors. As compared to the ReS₂ device, the responsivity and response speed is better by an order of magnitude. These results demonstrate the fabrication and application potential of Te/ReS₂ mixed-dimensional heterojunction for high-performance optoelectronic devices and sensors.