Nanoscale Imaging of Energy Transfer in Quantum Dots

Literature seminar abstract

Quantum Dots (QDs) are efficient light absorbers and emitters with tunable optoelectronic properties that show great promise in devices such as light emitting diodes, photodetectors, and photovoltaics. Energy transfer (ET) processes among individual QDs in large clusters and thin films are deeply responsible for the efficacy of these types of devices, yet the mechanisms involved are not well understood. In this talk, two different imaging techniques will be discussed that each elucidate different information about these ET processes. Using time-resolved ultrafast transient absorption microscopy, exciton diffusion can be directly imaged in CdSe QD superlattices1. A separate technique involving a combination of single molecule absorption and scanning tunneling microscopy images the energy pooling pathways from donor to acceptor QDs on a dot-by-dot basis2. Through these complementary imaging techniques, ET processes can be better studied in complicated systems of QDs, such as functioning devices.

(1)           Yoon, S. J.; Guo, Z.; dos Santos Claro, P. C.; Shevchenko, E. V.; Huang, L. ACS Nano 2016, 10 (7), pp 7208-7215.

(2)           Nguyen, D.; Nguyen, H. A.; Lyding, J. W.; Gruebele, M. ACS Nano 2017, 11 (6), pp 6328-6335.

Division(s): Physical

Speaker: David Thoma

Speaker Institution: Colorado State University

Event Date: 11-09-2017

Event Time: 4:00 PM

Event Location: Chemistry A101

Mixer Time: 3:45 PM

Mixer Location: Chemistry B101E

Host: A. Van Orden