Interface Properties of MoS van der Waals Heterojunctions with GaN.

The combination of the unique physical properties of molybdenum disulfide (MoS) with those of gallium nitride (GaN) and related group-III nitride semiconductors have recently attracted increasing scientific interest for the realization of innovative electronic and optoelectronic devices. A deep understanding of MoS/GaN interface properties represents the key to properly tailor the electronic and optical behavior of devices based on this heterostructure. In this study, monolayer (1L) MoS was grown on GaN-on-sapphire substrates by chemical vapor deposition (CVD) at 700 °C.

Large-Area MoS Films Grown on Sapphire and GaN Substrates by Pulsed Laser Deposition.

In this paper, we present the preparation of few-layer MoS films on single-crystal sapphire, as well as on heteroepitaxial GaN templates on sapphire substrates, using the pulsed laser deposition (PLD) technique. Detailed structural and chemical characterization of the films were performed using Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction measurements, and high-resolution transmission electron microscopy. According to X-ray diffraction studies, the films exhibit epitaxial growth, indicating a good in-plane alignment.

Multiscale Investigation of the Structural, Electrical and Photoluminescence Properties of MoS Obtained by MoO Sulfurization.

In this paper, we report a multiscale investigation of the compositional, morphological, structural, electrical, and optical emission properties of 2H-MoS obtained by sulfurization at 800 °C of very thin MoO films (with thickness ranging from ~2.8 nm to ~4.2 nm) on a SiO/Si substrate.

Gold nanoparticle assisted synthesis of MoS monolayers by chemical vapor deposition.

The use of metal nanoparticles is an established paradigm for the synthesis of semiconducting one-dimensional nanostructures. In this work we study their effect on the synthesis of two-dimensional semiconducting materials, by using gold nanoparticles for chemical vapor deposition growth of two-dimensional molybdenum disulfide (MoS). In comparison with the standard method, the employment of gold nanoparticles allows us to obtain large monolayer MoS flakes, up to 20 μm in lateral size, even if they are affected by the localized overgrowth of MoS bilayer and trilayer islands.

Nanoscale structural and electrical properties of graphene grown on AlGaN by catalyst-free chemical vapor deposition.

The integration of graphene (Gr) with nitride semiconductors is highly interesting for applications in high-power/high-frequency electronics and optoelectronics. In this work, we demonstrated the direct growth of Gr on AlGaN/sapphire templates by propane (CH) chemical vapor deposition at a temperature of 1350 °C. After optimization of the CH flow rate, a uniform and conformal Gr coverage was achieved, which proved beneficial to prevent degradation of AlGaN morphology.