nl401298s_si_002.pdf (10.86 MB)
Confined-but-Connected Quantum Solids via Controlled Ligand Displacement
journal contribution
posted on 2013-07-10, 00:00 authored by William
J. Baumgardner, Kevin Whitham, Tobias HanrathConfined-but-connected quantum dot
solids (QDS) combine the advantages
of tunable, quantum-confined energy levels with efficient charge transport
through enhanced electronic interdot coupling. We report the fabrication
of QDS by treating self-assembled films of colloidal PbSe quantum
dots with polar nonsolvents. Treatment with dimethylformamide balances
the rates of self-assembly and ligand displacement to yield confined-but-connected
QDS structures with cubic ordering and quasi-epitaxial interdot connections
through facets of neighboring dots. The QDS structure was analyzed
by a combination of transmission electron microscopy and wide-angle
and small-angle X-ray scattering. Excitonic absorption signatures
in optical spectroscopy confirm that quantum confinement is preserved.
Transport measurements show significantly enhanced conductivity in
treated films.