Anisotropic growth mechanism of tungsten diselenide domains using chemical vapor deposition method

• Published in: Applied surface science 2018-02, Vol.432, p.170-175
• Main Authors: Lee, Yoobeen, Jeong, Heekyung, Park, Yi-Seul, Han, Seulki, Noh, Jaegeun, Lee, Jin Seok
• Format: Article
• Language: English
• Subjects: Anisotropic morphology; Chemical vapor deposition; Kinetic energy; Transition metal dichalcogenide; WSe2
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2017.07.060

•WSe2 domains were grown on sapphire substrate by chemical vapor deposition utilizing WO3 and Se powders as precursors.•WSe2 domains was characterized by using Raman spectroscopy, PL, and AFM analysis.•The kinetic energies of precursors strongly influenced the morphology and size of the WSe2 domains formed during the growth process.•Anisotropic morphogenesis and edge terminations of WSe2 domains were investigated. Anisotropic transition metal dichalcogenide (TMDC) domains have stimulated a growing interest mainly due to their electronic properties that depend on the size, shape, and edge structures of the domains. In this work, we investigated the anisotropic morphogenesis and edge terminations of tungsten diselenide (WSe2) domains grown on sapphire substrates by chemical vapor deposition (CVD) using tungsten oxide (WO3) and selenium (Se) powders as precursors. We varied the amount of Se powder and growth temperature during the CVD process, which in turn caused variations in the growth mechanism and kinetic energies of precursors. We succeeded in synthesizing hexagonal, square, circular, and triangular anisotropic WSe2 domains. They were characterized using scanning electron microscopy (SEM), Raman spectroscopy, photoluminescence (PL) analyses, and atomic force microscopy (AFM). Furthermore, we proposed the growth mechanism of anisotropic WSe2 domains with different edge terminations based on experimental observations through scanning tunneling microscope (STM).