Photoluminescence efficiency of MBE-grown MoSe${}_2$ monolayers featuring sharp excitonic lines and diverse grain structures

Abstract

Recent studies have demonstrated that using h-BN as a substrate for the growth of transition metal dichalcogenides can significantly reduce excitonic linewidths. However, many other optical parameters still require optimization. In this work, we present a detailed study of the low-temperature photoluminescence efficiency of MBE-grown MoSe${}_2$ monolayers on h-BN substrates, comparing them to state-of-the-art exfoliated monolayers encapsulated in h-BN. We demonstrate that a quantitative comparison between samples requires accounting for interference effects and Purcell enhancement or suppression of the emission. By accounting for these effects in both photoluminescence and Raman signals, we show that the overall intrinsic luminescence efficiency is proportional to the sample coverage. Consequently, we find that exciton diffusion and edge effects are negligible in spectroscopy of MBE-grown samples, even for nanometer-sized crystals.

9 pages, 9 figures

References in corpus (18)

• Structural and Electrical Properties of MoTe${}_2$ and MoSe${}_2$ Grown by Molecular Beam Epitaxy
• Direct growth of single- and few-layer MoS2 on h-BN with preferred relative rotation angles
• Control of the Exciton Radiative Lifetime in van der Waals Heterostructures
• Molecular-beam epitaxy of monolayer and bilayer WSe2: A scanning tunneling microscopy/spectroscopy study and deduction of exciton binding energy
• Layer-by-layer epitaxial growth of scalable WSe2 on sapphire by molecular-beam epitaxy
• Optical spectroscopy of excited exciton states in MoS2 monolayers in van der Waals heterostructures
• Accessing high optical quality of MoS2 monolayers grown by chemical vapor deposition
• Highly-Oriented Atomically Thin Ambipolar MoSe${}_2$ Grown by Molecular Beam Epitaxy
• Band gap renormalization and work function tuning in MoSe2/hBN/Ru(0001) heterostructures
• Efficient cathodoluminescence of monolayer transitional metal dichalcogenides in a van der Waals heterostructure
• MBE growth of 2H-MoTe2 and 1T'-MoTe2 on 3D substrates
• Full orientation control of epitaxial MoS2 on hBN assisted by substrate defects
• Millimeter-scale layered MoSe2 grown on sapphire and evidence for negative magnetoresistance
• Indirect bandgap of hBN-encapsulated monolayer MoS2
• Magneto-spectroscopy of exciton Rydberg states in a CVD grown WSe2 monolayer
• Local field effects in ultrafast light-matter interaction measured by pump-probe spectroscopy of monolayer MoSe${}_2$
• Van der Waals solid phase epitaxy to grow large-area manganese-doped MoSe${}_2$ few-layers on SiO${}_2$/Si
• Molecular Beam Epitaxy growth of MoTe${}_2$ on Hexagonal Boron Nitride

Cited by in corpus (1)

• $WS{e}_2$ Monolayers Grown by Molecular Beam Epitaxy on hBN