To access the Zoom link, please contact Professor Felix Castellano at fncastel@ncsu.edu

About the Speaker:

Daniel Yonemoto is a senior graduate student in the Castellano lab studying interfacial light matter interactions in molecular decorated quantum dots. This is his 5th year in the chemistry department at NCSU and is originally from New Mexico.

About the Science:

Quantum−dot/molecule composites (QD/mol) have demonstrated useful photochemical properties for many photonic and optoelectronic applications, however, a comprehensive understanding of these materials remains elusive. This work introduces a series of cadmium(II) selenide/1-pyrenecarboxylic acid (CdSe/PCA) nanomaterials featuring bespoke PCA surface coverage on CdSe585 (coded by the peak of the first exciton absorption band) to glean insight into the QD/mol photophysical behavior. Tailoring the energy gap between the CdSe585 first exciton band (2.1 eV) and the lowest PCA triplet level (T1 = 2.0 eV) to be nearly isoenergetic, strong thermally activated delayed photoluminescence (TADPL) is observed resulting from reverse triplet-triplet energy transfer. The resultant average decay time constant (τobs) of the photoluminescence emanating from CdSe585 is deterministically controlled with surface-bound PCAn chromophores (n = average number of adsorbed PCA molecules) by shifting the triplet excited state equilibrium from the CdSe585 to the PCA molecular triplet reservoir as a function of n.

For more information about the speaker and the Castellano Group’s research, visit the group’s website:
https://castellgrp.wixsite.com/castellano-ncsu