nl9b03128_si_001.pdf (1.95 MB)
Faceting-Controlled Zeeman Splitting in Plasmonic TiO2 Nanocrystals
journal contribution
posted on 2019-08-29, 18:05 authored by Penghui Yin, Manu Hegde, Natalie S. Garnet, Yi Tan, Pavle V. RadovanovicDynamic
manipulation of discrete states in nanostructured materials
is critical for emerging quantum technologies. However, this process
often requires a correlation of mutually competing degrees of freedom.
Here we report the control of magnetic-field-induced excitonic splitting
in colloidal TiO2 nanocrystals by control of their faceting.
By changing nanocrystal morphology via reaction conditions, we control
the concentration and location of oxygen vacancies, which can generate
localized surface plasmon resonance and foster the reduction of lattice
cations leading to the emergence of individual or exchange-coupled
Ti(III) centers with high net-spin states. These species can all couple
with the nanocrystal lattice under different conditions resulting
in distinctly patterned excitonic Zeeman splitting and selective control
of conduction band states in an external magnetic field. This work
demonstrates the concept of using nanocrystal morphology to control
carrier polarization in individual nanocrystals using both intrinsic
and collective electronic properties, representing a unique approach
to multifunctionality in reduced dimensions.