Hide/Show Apps

Multiscale Self-Assembly of Silicon Quantum Dots into an Anisotropic Three-Dimensional Random Network

Download
2016-03-01
İlday, Serim Kayacan
İlday, Fatih Ömer
Huebner, Rene
Prosa, Ty J.
Martin, Isabelle
Nogay, Gizem
Kabacelik, Ismail
Mics, Zoltan
Bonn, Mischa
Turchinovich, Dmitry
Toffoli, Hande
Toffoli, Daniele
Friedrich, David
Schmidt, Bernd
Heinig, Karl-Heinz
Turan, Raşit
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.