Large‐area growth of multi‐layered MoS₂ for violet (∼405 nm) photodetector applications

Abstract

The two-dimensional multi-layered molybdenum disulfide (MoS 2 ) was grown over a large area by chemical vapor deposition process for violet ($405 nm) photodetector (PD) applications. The high-quality MoS 2 layers were successfully fabricated and transferred on HfO 2 /Si substrate. The inherent surface structure originated from the surface oxidation was also analyzed. The electrical properties of the multi-layered MoS 2 -based violet PDs with various channel widths (W ch ) were measured and compared under dark state and violet illumination operating at 405 nm. For the device with W ch of 4 mm, at the bias of À5 V, the photocurrent and on/off ratio were obtained to be 54.0 nA and 55.2, respectively. Under violet illumination, the photocurrent was $4.6 times higher compared to green illumination. At the bias of À5 V, the photoresponse properties of the device were characterized with average rise time and reset time of $55.7 and 46.0 s, respectively, during 4 cycles of operation.

2D Transition Metal Dichalcogenide Thin Films Obtained by Chemical Gas Phase Deposition Techniques

“…The Schottky barriers between the TMD film and graphene layers can be controlled to obtain electron and hole separation in the TMD layer because of the tunability of the work function of graphene via exfoliation methods . Furthermore, p–n van der Waals heterostructures, p–g–n heterostructures formed by graphene, and a thin p–n junction with a wide absorption spectrum, which are regarded as ways to break the shell, have been reported …”