Seminar by Dr. Siddhartha Sohoni, Department of Chemistry, University of Chicago on "Creation of Non-annihilating electronic biexcitons at room temperature"

27 Aug 2024
Seminar Room # 350, second floor annex

Speaker: Dr. Siddhartha Sohoni
Department of Chemistry, University of Chicago

Title: “Creation of Non-annihilating electronic biexcitons at
room temperature”.

Day and Date: Tuesday, August 27, 2024

Time: 12.00 pm.

Venue: Room no. 350, Chemistry Department
Second floor, Annex
------------------------------------------------------------------------

Talk Title : “Creation of Non-annihilating electronic biexcitons at room temperature”.
Abstract
When light interacts with matter, electronic excitations (excitons) form. An exciton is a Coulombically bound electron-hole pair. In high fluence, excitons can annihilate one another producing inefficient light harvesting and reduced dynamic range for optoelectronics. In this talk, I will describe our latest experiments that provide us with a post-synthetic chemical strategy to block exciton-exciton annihilation. This strategy allows us to switch reversibly between exciton annihilating and non-annihilating phases of the material. In the non-annihilating phase, two excitons reside on a single chromophore without interacting with each other effectively forming a biexciton state. We observe that this biexciton state remains stable throughout the excited-state lifetime of the chromophores. In the talk, I will also describe the latest quantum mechanical theory that explains the presence of these non-annihilating biexciton states.