Proceedings of nanoGe September Meeting 2015 (NFM15)
Publication date: 8th June 2015
The electronic properties of nanocrystals depend not only on the chemical composition, but also on size and shape. By choosing the reaction conditions and chemicals used in the synthesis, different sizes and shapes are obtained, ranging from 0D quantum dots to 1D nanorods and 2D nanosheets. Ultrathin 2-dimensional (2D) nanosheets (NSs) possess extraordinary properties that are attractive for both fundamental studies and technological devices. Colloidal 2D nanosheets have been successfully prepared in a variety of compositions, but the understanding of the growth mechanism, however, is underdeveloped.
Recently, we have demonstrated that the shape of Cu2–xS nanoparticles formed when dodecanethiol decomposes in the presence of a Cu-salt, changes from spherical nanocrystals to ultrathin nanosheets when halides are added [1]. The tentative model suggested that the halides stabilize the lamellar Cu-thiolate complexes to the extent where monomers for nucleation and growth are formed. Therefore, nucleation and growth is only allowed within the 2D constraints of the halide stabilized box. Although plausible, this mechanism is not yet supported by direct experimental evidence, which can only be obtained with in-situ X-ray measurements. Small-Angle X-ray Scattering (SAXS) was used to probe the columnar phase of the Cu-thiolate precursor with and without halides, while Wide-Angle X-ray Scattering (WAXS) yielded information on the crystallinity of the product Cu2-xS NCs.
We found that Cu2–xS is a very robust system to study with in-situ x-ray scattering. The desired nanocrystal geometries are obtained in a capillary, despite the difficulties to exactly reproduce the reaction conditions of the lab. By following the precursors and the formation of the NCs simultaneously, we have been able to verify our proposed mechanism with time-resolution. Therefore, our results give meaningful insights in the formation of 2-dimensional nanomaterials.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.