Bottom-up synthesis of nanowires through metal-catalyzed vapor phase epitaxy is a very attractive process to generate high-quality nanowires thus providing an additional degree of freedom in design of innovative devices that extend beyond what is achievable with the current technologies.
In this nano-fabrication process, nanowires grow through the condensation of atoms released from a molecular vapor (called precursors) at the surface of metallic nano-droplets. Gold is broadly used to form these nano-droplets. This self-assembly of nanowires takes place spontaneously at optimal temperature and vapor pressure and can be applied to synthesize any type of semiconductor nanowires. However, to functionalize these nanomaterials a precise introduction of impurities is central to tune their electronic and optical properties.For instance, the introduction of group III and V impurities in a silicon lattice is a crucial step for optimal design and performance of silicon nanowire technologies. The accurate control of this doping process remains an outstanding challenge that is increasingly complex as a result of the relentless drive toward device miniaturization and the emergence of novel nanoscale device architectures.
Besides the technological implications, this self-doping implies atomic scale processes that are crucial for the fundamental understanding of the catalytic assembly of nanowires. The scientists investigated this phenomenon at the atomistic-level using the emerging technique of highly focused ultraviolet laser-assisted atom-probe tomography to achieve three-dimensional atom-by-atom maps of individual nanowires. A new predictive theory of impurity injections was also developed to describe this self-doping phenomenon, which provides myriad opportunities to create entirely new class of nanoscale devices by precisely tailoring shape and composition of nanowires. The results of their breakthrough will be published in Nature.
About Polytechnique Montréal
Founded in 1873, Polytechnique Montréal is one of Canada's leading engineering teaching and research institutions. It is the largest engineering university in Québec for the size of its student body and the scope of its research activities. With over 40,000 graduates, Polytechnique Montréal has educated nearly one-quarter of the current members of the Ordre des ingénieurs du Québec. Polytechnique provides training in 15 engineering specialties, has 242 professors and more than 7,100 students. It has an annual operating budget of over $200 million, including a $72-million research budget.
Interviews with Professor Moutanabbir can be arranged.
Nathalie Rochette | EurekAlert!
Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University
TU Graz researchers show that enzyme function inhibits battery ageing
21.03.2017 | Technische Universität Graz
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy