Localized Exciton Anatomy and BandGap Energy Modulation in 1D MoS2 Nanostructures

Abstract

This study presents an in‐depth investigation of the electronic properties and bandgap energy distribution in 1D molybdenum disulfide (1D‐MoS2) nanostructures. Through a combination of high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) and electron energy‐loss spectroscopy (EELS), it reveals significant differences between 1D‐MoS2 nanostructures and their 2D counterparts, shedding light on their localized exciton behavior and their bandgap energy modulation within the nanostructures. Excitonic peaks at around 2 and 3 eV appear localized at the ends or along the sides of the 1D‐MoS2 nanostructures, while the plasmonic resonance at 8.3 eV retains its inner‐region localization. It demonstrates the spatial dependence of the bandgap energy, with the central region exhibiting a bandgap of approximately 1.2 eV, consistent with bulk MoS2, while regions characterized by curvature‐induced local strain fields exhibit instead a noticeable reduction. The findings provide valuable insights into the intricate relationship between excitonic behavior and bandgap sensitivity in 1D‐MoS2 nanostructures, streamlining the design and optimization of nanophotonic and optoelectronic devices.