Apr 24, 2024
11:15am - 11:30am
Room 344, Level 3, Summit
Boxuan Zhou1,Jingyuan Zhou1,Xiangfeng Duan1
University of California Los Angeles1
Boxuan Zhou1,Jingyuan Zhou1,Xiangfeng Duan1
University of California Los Angeles1
Molybdenum disulfide (MoS2) is an extensively studied two-dimensional layered semiconductor with interesting electronic and optical properties. Monolayer MoS2 features strong light-matter interactions due to its direct bandgap, whereas multilayer MoS2 is an indirect bandgap semiconductor and optically inactive. The molecular intercalation of MoS2 with organic cations offers a strategy to decouple the interlayer interaction, producing a bulk monolayer material, but is usually accompanied by a heavy electron doping effect that can diminish the intrinsic semiconductor properties or induce a phase transition. Herein, we report a chemical-dedoping strategy to tailor electron density in molecular-intercalated MoS2, therefore retaining monolayer properties. By introducing a poly(vinylpyrrolidone)-bromine complex during the electrochemical intercalation process, we show bulk monolayer MoS2 thin film can be produced with decoupled interlayer interaction and reduced electron concentration. The resulting thin films display strong excitonic emission, 20- and > 400 times stronger than the exfoliated monolayer and multilayer material respectively, as well as high valley polarization and enhanced photo-electric response. Our study opens a scalable path to large-area bulk monolayer MoS2 thin films with monolayer-like optical properties and greatly increased optical cross-section, presenting an attractive material platform for both fundamental photophysics studies and scalable optoelectronic applications.