Large-area epitaxial growth of MoSe₂ via an incandescent molybdenum source

We have developed an incandescent Mo source to fabricate large-area single-crystalline MoSe₂ thin films. The as-grown MoSe₂ thin films were characterized using transmission electron microscopy, energy dispersive x-ray spectroscopy, atomic force microscopy, Raman spectroscopy, photoluminescence (PL), reflection high energy electron diffraction (RHEED) and angular resolved photoemission spectroscopy (ARPES). A new Raman characteristic peak at 1591 cm^-1 was identified. Results from Raman spectroscopy, PL, RHEED and ARPES studies consistently reveal that large-area single crystalline mono-layer of MoSe₂ could be achieved by this technique. This technique enjoys several advantages over conventional approaches and could be extended to the growth of other two-dimensional layered materials containing a low-vapor-pressure element.