In:
Modern Physics Letters B, World Scientific Pub Co Pte Ltd, Vol. 30, No. 18 ( 2016-07-10), p. 1650267-
Abstract:
We report a systematic study of large-scale growth of high-quality WSe 2 atomic layers directly on SiO 2 /Si substrates using a convenient method. Various parameters, especially growth temperatures, flow rate of carrier gas and tube pressure, are investigated in affecting the properties of as-grown WSe 2 flakes in terms of their sizes, shapes and thickness. The pre-annealing step is demonstrated to be a key role in achieving the large-scale growth. Under an optimized condition, the lateral size of triangular single-crystal monolayer WSe 2 is up to 30 [Formula: see text]m and the area of the monolayer thin film can be up to 0.25 mm 2 . And some other interesting features, such as nanoflowers, are observed, which are a promising for catalyzing research. Raman spectrum and microphotoluminescence indicate distinct layer dependent efficiency. Auger electron spectroscopy (AES) studies demonstrate the atomic concentration of the as-grown WSe 2 . Electrical transport further shows that the [Formula: see text]-type WSe 2 field-effect transistors exhibit excellent electrical properties with carrier mobility of [Formula: see text][Formula: see text] 64 cm[Formula: see text]V[Formula: see text] s[Formula: see text] and current on/off ratio over 10 5 . These results are comparable to the exfoliated materials.
Type of Medium:
Online Resource
ISSN:
0217-9849
,
1793-6640
DOI:
10.1142/S0217984916502675
Language:
English
Publisher:
World Scientific Pub Co Pte Ltd
Publication Date:
2016
