Making optoelectronic and nanophotonic devices out of monolayer semiconductors requires processing of these fragile 2D materials. Usual processes involve creating heterostructures, transferring to a different substrate, or encapsulation in a dielectric superstrate.
Together with our TU/e collaborators, we have used fluorescence lifetime imaging to check the quality of WS2 after different processing steps. We find that the combination of a soft-transfer technique using a polymer stamp and emission lifetime measurements before and after processing allows us to optimize the quality of the devices, minimizing damage due to processing. Using this combination, we are also able to quantify the impact of different dielectric environments on the emission lifetime.
You can read the article in Advanced Optical Materials