STM study of point defects in two-dimensional CVD-grown semiconductor devices

Recent experimental studies of two-dimensional (2D) materials, otherwise known as van der Waals heterostructures, have shown promising results for the development of novel devices that exhibit exciting electronic, magnetic, and optical properties. One such group is the transition metal dichalcogenide (TMD) family which can manifest as either conducting or semiconducting. Semiconducting TMDs show promise to replace silicon as the semiconductor in electronic devices. These materials have shown to be reliably synthesized via the chemical vapor deposition (CVD) method. CVD grown TMDs host different defects that are absent in their exfoliated counterparts, allowing for defect engineering within the material. By studying these materials under a scanning tunneling microscope (STM), we can directly image the local density of states of TMD point defects in the presence of external fields, thus enabling a deep understanding of point defect electronic properties. In this talk, I will show our recent progress on a clean dry-transfer device fabrication method containing CVD grown 2D semiconducting TMDs and STM studies performed on these devices.