posted on 2016-02-11, 00:00authored bySerim Ilday, F. Ömer Ilday, René Hübner, Ty J. Prosa, Isabelle Martin, Gizem Nogay, Ismail Kabacelik, Zoltan Mics, Mischa Bonn, Dmitry Turchinovich, Hande Toffoli, Daniele Toffoli, David Friedrich, Bernd Schmidt, Karl-Heinz Heinig, Rasit Turan
Multiscale self-assembly is ubiquitous
in nature but its deliberate
use to synthesize multifunctional three-dimensional materials remains
rare, partly due to the notoriously difficult problem of controlling
topology from atomic to macroscopic scales to obtain intended material
properties. Here, we propose a simple, modular, noncolloidal methodology
that is based on exploiting universality in stochastic growth dynamics
and driving the growth process under far-from-equilibrium conditions
toward a preplanned structure. As proof of principle, we demonstrate
a confined-but-connected solid structure, comprising an anisotropic
random network of silicon quantum-dots that hierarchically self-assembles
from the atomic to the microscopic scales. First, quantum-dots form
to subsequently interconnect without inflating their diameters to
form a random network, and this network then grows in a preferential
direction to form undulated and branching nanowire-like structures.
This specific topology simultaneously achieves two scale-dependent
features, which were previously thought to be mutually exclusive:
good electrical conduction on the microscale and a bandgap tunable
over a range of energies on the nanoscale.