Synthesis and Characterization of Highly Crystalline Vertically Aligned WSe2 Nanosheets

Abstract

Here, we report on the synthesis of tungsten diselenide (WSe2) nanosheets using an atmospheric pressure chemical vapor deposition technique via the rapid selenization of thin tungsten films. The morphology and the structure, as well as the optical properties, of the so-produced material have been studied using electron microscopies, X-ray photoelectron spectroscopy, photoluminescence, UV–visible and Raman spectroscopies, and X-ray diffraction. These studies confirmed the high crystallinity, quality, purity, and orientation of the WSe2 nanosheets, in addition to the unexpected presence of mixed phases, instead of only the most thermodynamically stable 2H phase. The synthesized material might be useful for applications such as gas sensing or for hydrogen evolution reaction catalysis.

Impact of Pauli-blocking effect on optical limiting properties of WSe2 thin films

“…The peak corresponding to E 1 2g mode is associated with in-plane vibration of W and Se atoms, and the sharp peak corresponds to A 1g is related to out-of-plane vibration of Se atoms. The peak corresponding to B 1 2g mode is essentially due to vibration of W and Se atoms owing to the interlayer interactions [41][42][43][44]. All the peak intensities and shifts were calculated by fitting the Raman spectra with multiple peaks as shown in fig.…”

Atmospheric pressure chemical vapor deposition growth of vertically aligned SnS2 and SnSe2 nanosheets

“…The presence of a strong reducer, such as the H 2 , is mandatory for the selenization reaction, in contrast with the sulfurization reaction. 26 In a typical selenization process and as in the sulfurization reaction, the reactor is moved in order to place the Se powder at 450 °C into the oven, another Se powder is placed close to the Sn film sample at the same right temperature zone, with the argon and hydrogen flow for 30 minutes (Fig. S5 † ).…”

“…25) and WSe 2 (ref. 26) were synthesized vertically aligned to the substrate, with possible applications as gas sensors 27 or eld emission sources. 28 In the CVD method, different experimental geometries and strategies can be used leading to nanomaterials with different morphology, crystallinity (phase), crystal size, etc.29 This is also true for the CVD growth of metal dichalcogenides, here taking advantage of this unique characteristic of the CVD growth, the focus is done on tin dichalcogenide materials.…”

“… 25 ) and WSe 2 (ref. 26 ) were synthesized vertically aligned to the substrate, with possible applications as gas sensors 27 or field emission sources. 28 …”

Featuring the State of the Art of Nanosciences in Belgium

“…Vertically aligned nanosheets of WSe 2 were synthesized and characterized by Sierra-Castillo et al [6]. Using atmospheric pressure CVD for the selenization of W thin films on a sapphire substrate, they developed an efficient and scalable growth technique.…”