| Transition metal dichalcogenides (TMDs) and black phosphorous (black-P) are representative two dimensional (2D) materials with versatile electronic, optical, physical, and chemical properties that can be manipulated for novel electronic and optoelectronic device applications in nanoscale science and technology. However, many challenges remain associated with the nature of defects, crystal synthesis, thickness control, chemical stabilities, doping strategies, and Schottky contacts. This dissertation focuses on the surface and interface understanding of 2D materials to propose desired attributes and surface engineering to overcome those challenges. In particular, the interfacial qualities between the atomic layer deposited Al2O3 and black-P, MoTe2, or WTe2 are investigated by in situ X-ray photoelectron spectroscopy to lower the interfacial damage possibility. Then the chemical and structural properties of MoS2 under remote O2 plasma and thermal treatments are studied to propose a two-step atomic layer etching method. Also, the thermal and structural properties of MoTe2 are investigated to avoid thermal damage as well as explore possible phase engineering applications. |
