Exploration of Monolayer MoS2 Template-Induced Growth of GaN Thin Films via Plasma-Enhanced Atomic Layer Deposition

GaN thin films have been directly grown on monolayer MoS2 by plasma-enhanced atomic layer deposition at 260 degrees C using triethylgallium as the gallium precursor along with Ar/N-2/H-2 plasma for the first time. Mechanically exfoliated coalesced films of mono-MoS2 are characterized by Raman spectroscopy before and after the deposition. GaN shows a polycrystalline wurtzite structure through X-ray diffraction, whereas high-resolution transmission electron microscopy reveals that GaN has crystallized at the interface region with mono-MoS2 along the [0001] direction, exhibiting well-ordered lattice and sharp interface. This type of film growth on MoS2 template here is the evidence of the Stranski-Krastanov mode. In terms of the dependence of the growth rate and the surface morphologies on ALD cycles, we further concluded that the GaN growth can be divided into four phases, giving a deep insight into the growth mechanism of hybrid GaN/MoS2 system.

Automated summary

In this study, GaN thin films were grown directly on monolayer MoS2 for the first time using plasma-enhanced atomic layer deposition. Various characterization methods revealed the crystalline structure of GaN and the interface properties with mono-MoS2. The growth of GaN on MoS2 was found to follow the Stranski-Krastanov mode, with different growth phases observed depending on the ALD cycles.