5 research outputs found
Function Follows Form: From Semiconducting to Metallic toward Superconducting PbS Nanowires by Faceting the Crystal
In the realm of colloidal nanostructures, with its immense capacity for shape
and dimensionality control, the form is undoubtedly a driving factor for the
tunability of optical and electrical properties in semiconducting or metallic
materials. However, influencing the fundamental properties is still challenging
and requires sophisticated surface or dimensionality manipulation. In this
work, we present such a modification for the example of colloidal lead sulphide
nanowires. We show that the electrical properties of lead sulphide
nanostructures can be altered from semiconducting to metallic with indications
of superconductivity, by exploiting the flexibility of the colloidal synthesis
to sculpt the crystal and to form different surface facets. A particular
morphology of lead sulphide nanowires has been synthesized through the
formation of {111} surface facets, which shows metallic and superconducting
properties in contrast to other forms of this semiconducting crystal, which
contain other surface facets ({100} and {110}). This effect, which has been
investigated with several experimental and theoretical approaches, is
attributed to the presence of lead rich {111} facets. The insights promote new
strategies for tuning the properties of crystals as well as new applications
for lead sulphide nanostructures.Comment: 23 pages, 6 figure
Development of an interdisciplinary, intercultural master's program on sustainability:Learning from the richness of diversity
The purpose of this article is to describe a joint effort between three European and six Latin American universities to create an international Master's degree program on Sustainable Development and Management. Faculty members from these institutions are working together on this unusual and innovative project, which recognizes the importance of ICT (Information and Communication Technology) tools in international projects and programs. The article provides information about the ongoing interdisciplinary and intercultural dialogue and the learning process that is occurring throughout the development of the program.</p
From Dots to Stripes to Sheets: Shape Control of Lead Sulfide Nanostructures
Controlling anisotropy in nanostructures is a challenging but rewarding
task because confinement in one or more dimensions influences the
physical and chemical properties of the items decisively. In particular,
semiconducting nanostructures can be tailored to gain optimized properties
to work as transistors or absorber material in solar cells. We demonstrate
that the shape of colloidal lead sulfide nanostructures can be tuned
from spheres to stripes to sheets by means of the precursor concentrations,
the concentration of a chloroalkane coligand and the synthesis temperature.
All final structures still possess at least one dimension in confinement.
The structures cover all dimensionalities from 0D to 3D. Additionally,
the effect of temperature on the shape and thickness of PbS nanosheets
is shown and electrical transport measurements complement the findings
Function Follows Form: From Semiconducting to Metallic toward Superconducting PbS Nanowires by Faceting the Crystal
In the realm of colloidal nanostructures, with their immense capacity for shape and dimensionality control, the form is undoubtedly a driving factor for the tunability of optical and electrical properties in semiconducting or metallic materials. However, influencing the fundamental properties is still challenging and requires sophisticated surface or dimensionality manipulation. Such a modification is presented for the example of colloidal lead‐sulfide nanowires. It is shown that the electrical properties of lead sulfide nanostructures can be altered from semiconducting to metallic with indications of superconductivity, by exploiting the flexibility of the colloidal synthesis to sculpt the crystal and to form different surface facets. A particular morphology of lead sulfide nanowires is prepared through the formation of {111} surface facets, which shows metallic and superconducting properties in contrast to other forms of this semiconducting crystal, which contain other surface facets ({100} and {110}). This effect, which is investigated with several experimental and theoretical approaches, is attributed to the presence of lead‐rich {111} facets. The insights promote new strategies for tuning the properties of crystals and new applications for lead sulfide nanostructures