Repairing atomic vacancies in single-layer MoSe2 field-effect transistor and its defect dynamics

Two-dimensional materials: Repairing atomic defects via solution processing Defects can heavily influence the electrical transport properties of three-dimensional materials. But their impact becomes even more pronounced in low-dimensional systems. Fengqi Song and colleagues use a combination of calculations and experiments to show that a simple drop of a chemical solution can repair the selenium vacancies in field-effect transistors made from single layer molybdenum diselenide. By reducing the number of vacancies, which localize the electronic transport, the authors increased the carrier mobilities to nearly the intrinsic value by 2–3 orders of magnitude. The defect dynamics is visualized by the high resolution electron microscopy and multislice simulations. Such an approach could provide a route for enabling practical devices to be made from these relatively fragile materials.