Interfacial Contact with Noble Metal - Noble metal and Noble Metal – 2D Semiconductor Nanostructures Enhance Optical Activity

Student: Ricardo Romo

Degree: M.S., December 2019

Major Professor: Dr. Keith Roper

Research Area(s):

Photonics

Modeling & Simulation

View Research Quadslide

Background/Relevance

  • Nanoantenna-enhanced semiconductors exhibit extraordinary optical properties that allow nanoscale energy modulation (i.e. localized surface plasmon resonance (LSPR) and excitons.
  • Applications such as optical switching, drug delivery, environmental sensors and photocatalysis can be derived from strong and weak coupling between plasmons and excitons in transition metal dichalcogenide (TMD)-heterostructures.

Innovation

  • Distinguishing respective contributions of plasmonic heating and hot electron transfer in noble metal – TMD heterostructures via experimentally and computationally.

Approach

  • Produce TMD nanoflakes.
  • Scanning transmission electron microscope (STEM) of the TMD-heterostructures.
  • Perform far- and near-field maps of the TMD-heterostructures via Discrete Dipole Approximation (DDA).
  • Compare both computational and experimental optical feature enhancements.

Key Results

  • Mapped local electric fields and hot electron transfer in 2D materials in order to distinguish relative thermal and hot electron transfer dissipation from LSPR.
  • Distinguished respective contributions of electron transfer and plasmonic heating from DDA simulations.

Conclusions

  • These tools allowed comparison between the metal nanoantenna and the DDA simulations to determine relative contributions of plasmonic heating and hot electron transport to increase LSPR-enhanced photocatalysis from the TMD-heterostructure.

Future Work

  • Possible x-ray photoelectron spectroscopy (XPS), atomic force microscopy, and Raman spectroscopy to improve understanding of photoinduced doping of TMDs by metal nanoantennae.