High-Performance Devices Based on InSe-In1-xGaxSe Van der Waals Heterojunctions

2D Layered Material Alloys: Synthesis and Application in Electronic and Optoelectronic Devices

2D layered materials (2DLMs) have come under the limelight of scientific and engineering research and broke new ground across a broad range of disciplines in the past decade. Nevertheless, the members of stoichiometric 2DLMs are relatively limited. This renders them incompetent to fulfill the multitudinous scenarios across the breadth of electronic and optoelectronic applications since the characteristics exhibited by a specific material are relatively monotonous and limited. Inspiringly, alloying of 2DLMs can markedly broaden the 2D family through composition modulation and it has ushered a whole new research domain: 2DLM alloy nano-electronics and nano-optoelectronics. This review begins with a comprehensive survey on synthetic technologies for the production of 2DLM alloys, which include chemical vapor transport, chemical vapor deposition, pulsed-laser deposition, and molecular beam epitaxy, spanning their development, as well as, advantages and disadvantages. Then, the up-to-date advances of 2DLM alloys in electronic devices are summarized. Subsequently, the up-to-date advances of 2DLM alloys in optoelectronic devices are summarized. In the end, the ongoing challenges of this emerging field are highlighted and the future opportunities are envisioned, which aim to navigate the coming exploration and fully exert the pivotal role of 2DLMs toward the next generation of electronic and optoelectronic devices.

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

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) p-type tellurium (Te) and 2D n-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 p-n 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.