Structure and Properties of Single-Layer MoS2 for Nano-Photoelectric Devices

Abstract

To meet the need for preparing high-performance nano-optoelectronic devices based on single-layer MoS2, the effects of the heating method (one-step or two-step heating) and the temperature of the MoO3 source on the morphology, size, structure, and layers of an MoS2 crystal grown on a sapphire substrate using chemical vapor deposition are studied in this paper. The results show that MoS2 prepared by two-step heating (the heating of the S source starts when the temperature of the MoO3 source rises to 837 K) is superior over that of one-step heating (MoO3 and S are heated at the same time). One-step heating tends to form a mixture of MoO2 and MoS2. Neither too low nor too high of a heating temperature of MoO3 source is conducive to the formation of MoS2. When the temperature of MoO3 source is in the range of 1073 K to 1098 K, the size of MoS2 increases with the rise in temperature. A uniform large-sized triangle with a side length of 100 μm is obtained when the heating temperature of MoO3 is 1098 K. The triangular MoS2 crystals grown by the two-step heating method have a single-layer structure.

Simultaneous Enhancement of Charge Separation and Hole Transportation in a W:α-Fe2O3/MoS2 Photoanode: A Collaborative Approach of MoS2 as a Heterojunction and W as a Metal Dopant

“…This change in the crystal structure of the MoS 2 layer can be attributed to increasing the concentration of the MoS 2 nanosheets on the surface of the α-Fe 2 O 3 photoanode by dropping several times. In Figure b,c, MoS 2 surrounding 0.5W:α-Fe 2 O 3 indicated that the MoS 2 layer was composed of stacked nanosheets. , Further, the STEM and EDX elemental mapping results of the 0.5W:α-Fe 2 O 3 /MoS 2 nanorods show the presence of all elements, which confirms the X-ray photoelectron spectroscopy (XPS) analysis results.…”

“…In Figure 3b,c, MoS 2 surrounding 0.5W:α-Fe 2 O 3 indicated that the MoS 2 layer was composed of stacked nanosheets. 28,29 Further, the STEM and EDX elemental mapping results of the 0.5W:α-Fe 2 O 3 /MoS 2 nanorods show the presence of all elements, which confirms the Xray photoelectron spectroscopy (XPS) analysis results.…”

2D Semiconductor Nanomaterials and Heterostructures: Controlled Synthesis and Functional Applications

“…The first MoS 2 nanofilm was fabricated by ALD in 2015. Initially, the number of MoS 2 layers was controlled by the tuning of parameters of ALD technique [ 106 , 108 – 110 ]. Later, the ALD synthesis of TMDCs monolayer was reported [ 111 – 114 ].…”

Anisotropic Mechanical Properties of 2-D Materials

“…In contrary to chemically inert graphene with no intrinsic bandgap, MoS 2 with layered structure is one transition metal dichalcogenide. MoS 2 has been often synthesized using chemical vapor deposition (CVD) and its reaction principle involves first the transformation of solid-state MoO 3 and sublimed surfur to gas state and then the mixed gases driven by argon caused the formation of gasphase MoO 3-x and MoS 2 and eventually the formation of solid-state MoS 2 , the reactions of which is expressed as [3]:…”