Nanowerk  April 11, 2024 The exact role of h-BN encapsulation in relation to the internal defects of 2D semiconductors in hexagonal boron nitride (h-BN) remains unclear. An international team of researchers (South Korea, Japan) reported that h-BN encapsulation greatly removes the defect-related gap states by stabilizing the chemisorbed oxygen molecules onto the defects of monolayer tungsten disulfide (WS2) crystals. Studies showed that h-BN encapsulation prevented the desorption of oxygen molecules over various excitation and ambient conditions, resulting in a greatly lowered and stabilized free electron density in monolayer WS2 crystals. This suppressed the exciton annihilation processes by two orders of […]