Synthesis of Atomically Thin ${\bf MoS}_{\bf 2}$ Triangles and Hexagrams and Their Electrical Transport Properties

Autor: Mihrimah Ozkan, Wei Wang, Darshana Wickramaratne, Lauro Zavala, Isaac Ruiz, Mahesh R. Neupane, Roger K. Lake, Cengiz S. Ozkan, Zafer Mutlu, Robert Ionescu, Yu Chai, Zachary Favors
Rok vydání: 2014
Předmět:
Zdroj: IEEE Transactions on Nanotechnology. 13:749-754
ISSN: 1941-0085
1536-125X
DOI: 10.1109/tnano.2014.2319081
Popis: Atomically thin molybdenum disulfide (MoS 2 ) triangles and hexagrams were prepared by a two-step growth ambient pressure chemical vapor deposition (APCVD) process. Molybdenum Trioxide (MoO 3 ) nanobelts, a few microns in length and width, were prepared using a hydrothermal technique and utilized as the starting material. High temperature treatment of the MoO 3 nanobelts followed by a rigorous sulfurization via APCVD processing provided different morphologies of MoS 2 monolayers and bilayer (BL) sheets. Triangle and hexagram morphologies were characterized using Raman spectroscopy, photoluminescence (PL) measurements, scanning electron microscopy and atomic force microscopy (AFM). The regrowth step in the CVD process was proven to be ideal in enlarging the grain size. PL and Raman spectroscopy and AFM results confirmed the presence of monolayer and BL regions in the regrowth growth process. Triangle and hexagram domains are observed to be cooperatively nucleating and coalescing together to form large-area layers. Furthermore, the electrical transport properties of the synthesized MoS 2 layers were studied. Electron mobility based on back gated field effect transistors was measured to be approximately 0.02 cm 2 /V. S.
Databáze: OpenAIRE