AVS 64th International Symposium & Exhibition
    2D Materials Focus Topic Friday Sessions
       Session 2D+MI+NS+SS+TF-FrM

Invited Paper 2D+MI+NS+SS+TF-FrM1
Electro-optics with 2D Semiconductors and Heterostructures

Friday, November 3, 2017, 8:20 am, Room 15

Session: Nanostructures including Heterostructures and Patterning of 2D Materials
Presenter: Goki Eda, National University of Singapore, Singapore
Correspondent: Click to Email

Despite being only a few atoms thick, two-dimensional (2D) semiconductors such as monolayer MoS2 and phosphorene exhibit distinctly strong light-matter interaction compared to their bulk counterparts. Excitons and their complexes with giant oscillator strength play a fundamental role in mediating the strong coupling between light and a 2D semiconductor. These excitons are stable at room temperature and make 2D semiconductors attractive for a number of photonic devices including ultra-fast photo-detectors, optical modulators, on-chip photonic circuits, flexible photovoltaic devices, chiral light emitters, single photon sources, and ultra-low threshold lasers1. In order for these devices to be integrated for photonic devices, practical schemes for electrical generation, manipulation, and detection of excitons need to be developed. We create artificial quantum wells based on van der Waal heterostructures and investigate the dynamics of 2D excitons under various conditions to achieve the desired photonic functionalities. In this talk, I will start by discussing our findings on the ultrafast dipole-dipole energy transfer processes involving 2D excitons. I will show that exciton-exciton energy transfer in hetero-bilayers is among the fastest measured in nanomaterials2. Peculiar optical effects arising from strong exciton-plasmon coupling in 2D semiconductors hybridized with metal nanoparticles will also be discussed3. Finally, our recent efforts in realizing electro-optical (electroluminescence, electro-absorption, and Pockels effect) devices will be discussed. I will share our views on the potential advantages of 2D semiconductors over other materials and discuss our outlook for further studies.

References:

  1. 1. F. Xia et al. “Two-dimensional material nanophotonics” Nat. Phot. 8, 899 (2016).
  2. 2. D. Kozawa et al. "Efficient interlayer energy transfer via 2D dipole coupling in MoSe2/WS2 heterostructures" Nano Lett. 16, 4087 (2016).
  3. 3. W. Zhao et. al. “Exciton-plasmon coupling and electromagnetically induced transparency in monolayer semiconductors hybridized with Ag nanoparticles” Adv. Mater. 28, 2709 (2016).