Sunday, November 11, 2018

Dr. Bhoj Gautam's Talk on Structure-property relationships in organic semiconductors for photo-voltaic applications


ANPA Monthly Colloquium Series Presents
Dr. Bhoj Gautam
Fayetteville State University, Fayetteville, NC, USA


Saturday, November 17, 2018 @ 9 PM EST.

Abstract 
Organic semiconductors have been intensively studied due to their unique electronic and optical properties. Their properties – including relatively easy and inexpensive fabrication, lightweight, mechanical flexibility and compatibility with stretchability, and non-toxic processing methods – open broad prospects for their applications in light emission, energy conversion, thin-film electronics and other fields. The mechanism(s) by which charges are created by photoabsorption in these materials is different from that in the inorganic semiconductors. The charge generation process in these materials requires the donor-acceptor (D-A) heterojunction and involves the formation of neutral excitons through light absorption, exciton diffusion and formation of charge transfer (CT) complex and its subsequent splitting into “free” electrons and holes at the D-A interface. In this talk, I will discuss the charge generation process that involves these intermediate states using ultrafast pump-probe spectroscopy to understand the photoconversion process in these systems. Specifically, I will talk about the impact of polymer conformation, molecular architecture of acceptors, and nano-morphology on interface electronic properties in connection with charge separation dynamics. I will discuss how such studies have impacted the development of improved solar cell devices and the design of organic electronic device structures for inexpensive and flexible solar cell applications. 

Members will be sent the Webex link via e-mail a couple of days before the talk.