Ultrabroadband Photodetection with MoS and Gold Nanorod Using Gap-Mode Plasmon Effect.

Plasmon resonance using metal nanostructures enables the realization of high-performance optoelectronic devices via field enhancements in the vicinity of the metal nanostructure. This study proposes an ultrabroadband MoS photodetector based on the gap-mode plasmon of gold nanorods. The use of MoS as a gap spacer for the gap-mode plasmon effect and as a channel material for the photodetector is demonstrated.

Photoconductivity Switching in MoTe/Graphene Heterostructure by Trap-Assisted Photogating.

Negative photoconductivity (NPC), a reduction in photoconductivity under light illumination, could provide low power consumption and high-speed frequency response. The NPC has been generally observed in low-dimensional materials, which can be easily affected by the trapping of photocarriers. However, a gradual transition between NPC and positive photoconductivity (PPC) by controlling the light intensity has not been reported.

Ultrasensitive Phototransistor Based on WSe-MoS van der Waals Heterojunction.

Band engineering using the van der Waals heterostructure of two-dimensional materials allows for the realization of high-performance optoelectronic devices by providing an ultrathin and uniform PN junction with sharp band edges. In this study, a highly sensitive photodetector based on the van der Waals heterostructure of WSe and MoS was developed. The MoS was utilized as the channel for a phototransistor, whereas the WSe-MoS PN junction in the out-of-plane orientation was utilized as a charge transfer layer.

High-Performance Field-Effect Transistor and Logic Gates Based on GaS-MoS van der Waals Heterostructure.

This work demonstrates a high-performance and hysteresis-free field-effect transistor based on two-dimensional (2D) semiconductors featuring a van der Waals heterostructure, MoS channel, and GaS gate insulator. The transistor exhibits a subthreshold swing of 63 mV/dec, an on/off ratio over 10 within a gate voltage of 0.4 V, and peak mobility of 83 cm/(V s) at room temperature.

Flexible and Transparent Thin-Film Transistors Based on Two-Dimensional Materials for Active-Matrix Display.

Two-dimensional (2D) materials have attracted significant attention because of their outstanding electrical, mechanical, and optical characteristics. Because all of the conducting (graphene), semiconducting (molybdenum disulfide, MoS), and insulating (hexagonal boron nitride, h-BN) components can be constructed from 2D materials, thin-film transistors based on 2D materials (2D TFTs) have been developed. However, scaling-up is necessary for these technologies to go beyond their initial implementation using the mechanical exfoliation method.

Observation of Wavelength-Dependent Quantum Plasmon Tunneling with Varying the Thickness of Graphene Spacer.

Plasmonic coupling provides a highly localized electromagnetic field in the gap of noble metals when illuminated by a light. The plasmonic field enhancement is generally known to be inversely proportional to the gap distance. Given such a relation, reducing the gap distance appears to be necessary to achieve the highest possible field enhancement.

Si-MoS Vertical Heterojunction for a Photodetector with High Responsivity and Low Noise Equivalent Power.

In this study, we propose the fabrication of a photodetector based on the heterostructure of p-type Si and n-type MoS. Mechanically exfoliated MoS flakes are transferred onto a Si layer; the resulting Si-MoS p-n photodiode shows excellent performance with a responsivity ( R) and detectivity ( D*) of 76.1 A/W and 10 Jones, respectively.

Atomic-scale etching of hexagonal boron nitride for device integration based on two-dimensional materials.

Hexagonal boron nitride (h-BN) is considered an ideal template for electronics based on two-dimensional (2D) materials, owing to its unique properties as a dielectric film. Most studies involving h-BN and its application to electronics have focused on its synthesis using techniques such as chemical vapor deposition, the electrical analysis of its surface state, and the evaluation of its performance. Meanwhile, processing techniques including etching methods have not been widely studied despite their necessity for device fabrication processes.