Semiconductor nanowires self-assembled from colloidal CdTe nanocrystal building blocks: optical properties and application perspectives

Solution-based self-assembly of quasi-one-dimensional semiconductor
nanostructures (nanowires) from quasi-zero-dimensional (quantum
dots) colloidal nanocrystal building blocks has proven itself as a
powerful and flexible preparation technique. Polycrystalline CdTe
nanowires self-assembled from light-emitting thiol-capped CdTe
nanocrystals are the focus of this Feature Article. These nanowires
represent an interesting model system for quantum dot solids, where
electronic coupling between the individual nanocrystals can be
optically accessed and controlled. We provide a literature-based
summary of the formation mechanism and the morphology-related
aspects of self-assembled CdTe nanowires, and highlight several
fundamental and application-related optical properties of these
nanostructures. These include fundamental aspects of polarization
anisotropies in photoluminescence excitation and emission, the
electronic coupling between individual semiconductor nanocrystals
constituting the nanowires, and more applied, waveguiding
properties of CdTe nanowire bundles and anti-Stokes
photoluminescence in a prototypical structure of co-axial
nanowires. The optical properties of self-assembled CdTe nanowires
considered here render them potential candidates for photonic
nanoscale devices.