Investigating and Manipulating Polaritons using Site Basis Spectroscopy and Photocurrent Device Design
Abstract
We propose a project that utilizes semiconducting carbon nanotubes thin films, ultrafast 2D White-Light spectroscopy, and novel device architectures to explore polariton photophysics and to test new technologies that utilize polaritons. Exciton-polaritons are hybrid states formed when molecular excitons are strongly coupled to photons confined in an optical cavity, giving rise to properties not observed in the molecular excitons themselves. They are receiving much attention across a wide swath of chemistry, physics, and material science, but the fundamental principles behind polariton photophysics are still under debate. The key to interpreting polariton photophysics is deducing the composition of the delocalized wavefunctions and understanding the kinetics of energy transfer between the polariton eigenstates. A key difficulty is measuring the many dark states. In this proposal, we outline new approaches for measuring the coefficients of the wavefunctions, whether bright or dark, by using nanotubes’ second interband excitons (the S22 states) and by measuring photocurrent in devices made in polariton cavities. These two approaches are indifferent to whether an optical transition is dark or bright and thus can probe energy pathways not accessible to conventional optical techniques. We are also eager to exploit polariton photophysics to alter electrical conductivity. We envision a new type of field effect transistor in which the voltages applied to the device are used to modulate the density of charges and to drive light matter coupling induced changes to the mobility and-or injection of those charges. Success could lead to low-energy transistors that operate below the thermodynamic limit of conventional transistors. Our approach of carbon nanotube thin films, 2D WL spectroscopy, and photocurrent devices will provide new insights into the fundamental physics of polaritons and explore a new application.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 29, 2024
- Source ID
- FA95502310181
Entities
People
- Martin T. Zanni
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Wisconsin System