Ambient Pressure Chemical Vapor Deposition of Flat and Vertically Aligned MoS 2 Nanosheets.

Molybdenum disulfide (MoS 2 ) got tremendous attention due to its atomically thin body, rich physics, and high carrier mobility. The controlled synthesis of large area and high crystalline monolayer MoS 2 nanosheets on diverse substrates remains a challenge for potential practical applications. Synthesizing different structured MoS 2 nanosheets with horizontal and vertical orientations with respect to the substrate surface would bring a configurational versatility with benefit for numerous applications, including nanoelectronics, optoelectronics, and energy technologies. Among the proposed methods, ambient pressure chemical vapor deposition (AP-CVD) is a promising way for developing large-scale MoS 2 nanosheets because of its high flexibility and facile approach. Here, we show an effective way for synthesizing large-scale horizontally and vertically aligned MoS 2 on different substrates such as flat SiO 2 /Si, pre-patterned SiO 2 and conductive substrates (TaN) benefit various direct TMDs production. In particular, we show precise control of CVD optimization for yielding high-quality MoS 2 layers by changing growth zone configuration and the process steps. We demonstrated that the influence of configuration variability by local changes of the S to MoO 3 precursor positions in the growth zones inside the CVD reactor is a key factor that results in differently oriented MoS 2 formation. Finally, we show the layer quality and physical properties of as-grown MoS 2 by means of different characterizations: Raman spectroscopy, scanning electron microscopy (SEM), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). These experimental findings provide a strong pathway for conformally recasting AP-CVD grown MoS 2 in many different configurations (i.e., substrate variability) or motifs (i.e., vertical or planar alignment) with potential for flexible electronics, optoelectronics, memories to energy storage devices.