Observation
of Photoinduced Charge Transfer in Novel
Luminescent CdSe Quantum Dot–CePO<sub>4</sub>:Tb Metal Oxide
Nanowire Composite Heterostructures
- Publication date
- Publisher
Abstract
We report on the synthesis, structural
characterization, and intrinsic
charge transfer processes associated with novel luminescent zero-dimensional
(0D) CdSe nanocrystal–one-dimensional (1D) CePO<sub>4</sub>:Tb nanowire composite heterostructures. Specifically, ∼4
nm CdSe quantum dots (QDs) have been successfully anchored onto high-aspect
ratio CePO<sub>4</sub>:Tb nanowires, measuring ∼65 nm in diameter
and ∼2 μm in length. Composite formation was confirmed
by high-resolution transmission microscopy, energy-dispersive X-ray
spectroscopy mapping, and confocal microscopy. Photoluminescence (PL)
spectra, emission decay, and optical absorption of these nanoscale
heterostructures were collected and compared with those of single,
discrete CdSe QDs and CePO<sub>4</sub>:Tb nanowires. We show that
our composite heterostructure evinces both PL quenching and a shorter
average lifetime as compared with unbound CdSe QDs and CePO<sub>4</sub>:Tb nanowires. We propose that a photoinduced 0D–1D charge
transfer process occurs between CdSe and CePO<sub>4</sub>:Tb and that
it represents the predominant mechanism, accounting for the observed
PL quenching and shorter lifetimes noted in our composite heterostructures.
Data are additionally explained in the context of the inherent energy
level alignments of both CdSe QDs and CePO<sub>4</sub>:Tb nanowires