Robert Burke1 2 Kehao Zhang3 Dmitry Ruzmetov1 Andrew Herzing4 Mahesh Neupane1 Anthony Birdwell1 Terrance O'Regan1 Berc Kalanyan4 Matthew Chin1 Alexander Mazzoni1 Scott Walck1 Michael Valentin1 5 Barbara Nichols1 Albert Davydov4 Joshua Robinson3 Tony Ivanov1 Madan Dubey1

1, U.S. Army Research Laboratory, Adelphi, Maryland, United States
2, General Technical Services, LLC, Wall, New Jersey, United States
3, The Pennsylvania State University, University Park, Pennsylvania, United States
4, National Institute of Standards and Technology, Gaithersburg, Maryland, United States
5, University of California, Riverside, Riverside, California, United States

To date, transition metal dichalcogenides (TMDs) have been synthesized on a variety of substrates including SiO2, quartz, sapphire, mica, and gold foils. However, synthesis on these substrates typically leads to polycrystalline films due to the random orientation of the triangular domains. Epitaxial growth has been achieved on annealed sapphire substrates, but sapphire is not a suitable substrate if one wants to explore 2D/3D vertical semiconductor heterostructures. III-nitrides, on the other hand, can be an active component of a 2D/3D vertical heterostructure and also possess a small lattice mismatch with a variety of TMDs. As a result, synthesis of TMDs on III-nitrides can lead to epitaxial growth of aligned triangles on a 3D semiconductor substrate. In this talk, we will discuss the synthesis of molybdenum disulfide (MoS2) on n-type and p-type GaN via powder vaporization (PV). We will show epitaxial growth of aligned MoS2 triangles on both n-type and p-type GaN and the importance of sample preparation in achieving epitaxial growth. We will also present our findings involving the characterization of the MoS2 triangles using techniques such as scanning electronic microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, photoluminescence (PL), conductive atomic force microscopy (CAFM), x-ray photoelectron spectroscopy (XPS), modeling, and transmission electron microscopy (TEM).