Localized Gradual Photomediated Brightness and Lifetime Increase of Superacid-Treated Monolayer MoS.

Monolayer semiconducting transition-metal dichalcogenides (S-TMDs) have been extensively studied as materials for next-generation optoelectronic devices due to their direct band gap and high exciton binding energy at room temperature. Under a superacid treatment of bis(trifluoromethane)sulfonimide (TFSI), sulfur-based TMDs such as MoS can emit strong photoluminescence (PL) with a photoluminescence quantum yield (PLQY) approaching unity. However, the magnitude of PL enhancement varies by more than 2 orders of magnitude in published reports.