Colloquium: “2D Materials in the Spot ‘Light’: The Emergence of Advanced Optical and Electronic Functionalities”
Dr. Sharmila Shirodkar
Postdoctoral Research Associate
Department of Materials Science and NanoEngineering
Rice University, Houston, TX
George P. Williams, Jr. Lecture Hall, (Olin 101)
Wednesday, February 5, 2020 at 3:00 PM
There will be a reception in Olin Lounge at approximately 4 PM following the colloquium. All interested persons are cordially invited to attend.
Moore’s law that dictated the miniaturization in silicon electronics since 1965, has begun to fail in recent years indicating approaching limit in size reduction of conventional silicon-based electronics. To overcome this obstacle, scientific efforts have been focused on potential silicon replacement – “two-dimensional” (2D) materials, that exhibit exotic properties due to quantum confinement effects, leading to enhanced response to external fields. Using first-principles theory, I will discuss the emergence of exceptional optical, plasmonic and electronic properties in 2D materials, and their technological applications. First, building on simple electronic models, I will show how dimensionality affects the maximum achievable reflectance and absorbance in 2D materials . Amazingly, dimensionality reduction strikingly amplifies properties of some materials for use as ultrathin reflectors and absorbers in various frequency ranges of the electromagnetic spectrum, that surpass the performance of conventional thin films. Furthermore, by tuning the free carrier density in 2D metals, I will show that light-matter interaction induces visible frequency plasmons that allow nanoplasmonic devices to squeeze information with 100 times higher resolution , . Finally, I will discuss how the enhancement of electron-phonon coupling gives rise to robust ferroelectricity in 2D metal dichalcogenides . The ability to support out of plane polarization in the 2D limit opens up possibility of nanoscale dipolectronic devices. Harnessing the exceptional structure-property relationships, our work explores the fundamental physics behind advanced functionalities in 2D materials, that find promising applications in technological areas of nanoelectronics, nanoplasmonics to optoelectronics.
 S. Gupta, S. N. Shirodkar, A. Kutana, and B. I. Yakobson, “In Pursuit of 2D Materials for Maximum Optical Response,” ACS Nano, vol. 12, no. 11, pp. 10880–10889, Nov. 2018, doi: 10.1021/acsnano.8b03754.
 Y. Huang, S. N. Shirodkar, and B. I. Yakobson, “Two-Dimensional Boron Polymorphs for Visible Range Plasmonics: A First-Principles Exploration,” J. Am. Chem. Soc., vol. 139, no. 47, pp. 17181–17185, Nov. 2017, doi: 10.1021/jacs.7b10329.
 S. N. Shirodkar, M. Mattheakis, P. Cazeaux, P. Narang, M. Soljačić, and E. Kaxiras, “Quantum plasmons with optical-range frequencies in doped few-layer graphene,” Phys. Rev. B, vol. 97, no. 19, May 2018, doi: 10.1103/PhysRevB.97.195435.
 S. N. Shirodkar and U. V. Waghmare, “Emergence of Ferroelectricity at a Metal-Semiconductor Transition in a 1 T Monolayer of MoS2,” Phys. Rev. Lett., vol. 112, no. 15, p. 157601, Apr. 2014, doi: 10.1103/PhysRevLett.112.157601.