Chemical Physics Seminar: Organic Interfaces and Defect Healing of 2D Semiconductors
Prof. Doron Naveh, Head of Nanoelectronics program at the Faculty of Engineering, Bar-Ilan University
Over the past decade two-dimensional transition metal dichalcogenide (TMDC) semiconductors have attracted much attention owing to their unique electronic structure and to their potential application in next generation electronic and optoelectronics devices. Typically, TMDC semiconductors have a characteristic intrinsic carrier density originating from radical adsorption at the chalcogen vacancy sites. These shallow defects are a source for carrier scattering degrading the transport and for recombination centers resulting in high order many-body phenomena such as charged optical excitations. Interestingly, chalcogen vacancies can be utilized as anchoring sites for organic molecules, providing a knob for tuning the spectra of defect levels of two-dimensional TMDC semiconductors. Here, the recent study on thiol passivation of WSe2 will be discussed in detail. We quantify the vacancy defect density and their energy spectra and ultimately the removal of defect states and Fermi-level shift of defect-free WSe2 monolayers.