Emergent Phenomena in Old Materials
Kevin
Kittilstved
Department
of
Chemistry
University
of
Massachusetts
Amherst
Tuesday,
January
14,
2019
10:00
a.m.
C2-361
(Reading
Room)
Abstract:
The electronic structure and functionality of semiconductors is very sensitive to the presence of defects in the lattice. Aliovalent transition metal dopants in bulk oxide semiconductors are well-known multifunctional materials with potential application in visible light photocatalysis, spintronics and optoelectronics. However, these types of materials have received little attention as nanocrystalline materials. In this talk, I will present our recent work on the synthesis and characterization of transition-metal dopants in colloidal metal oxide nanocrystals. We have discovered unique electronic structures that can be easily exploited in this class of aliovalent diluted magnetic semiconductors. I will also demonstrate the tunability and reversibility of this post-synthetic modification of the nanocrystals to study emergent interactions between dopants and free carriers in these materials. In conclusion, I will compare these aliovalent DMSs to the more common isovalent DMSs.