U. SHEFFIELD (UK) — With a new tool, scientists can analyze nanostructures at an unprecedented level of detail without destroying them in the process, say researchers.
The nuclear magnetic resonance apparatus—developed by the University of Sheffield department of physics and astronomy—will allow for further developments and new applications for nanotechnology which is increasingly used in harvesting solar energy, computing, communication developments, and also in the medical field.
Their findings are published in Nature Nanotechnology.
Alexander Tartakovskii, who led the team of researchers, says: “We have developed a new important tool for microscopy analysis of nanostructures. The very tiny quantities of matter used in nanostructures—the behavior of electrons and photons—is governed by new quantum effects, quite different from what happens in bulk materials.
“Development requires careful structural analysis, in order to understand how the nanostructures are formed, and how we can build them to enhance and control their useful properties.
“Existing structural analysis methods, key for the research and development of new materials, are invasive: a nanostructure would be irreversibly destroyed in the process of the experiment, and, as a result, the important link between the structural and electronic or photonic properties would usually be lost.
“This limitation is now overcome by our new techniques, which rely on inherently non-invasive nuclear magnetic resonance (NMR) probing.”
The results open a new way of nano-engineering, a full characterization of a new material and new semiconductor nano-device without destroying them meaning more research and development and device fabrication processes.
Tarakovskii adds: “We have developed new techniques which allowed unprecedented sensitivity and enhancement of the NMR signal in nanostructures. Particular nanostructures of interest in our research are semiconductor quantum dots, which are researched widely for their promising photonic applications, and potential for the use in a new type of computer hardware employing quantum logic.
“The result of our experiments was quite unexpected and changed our understanding of the architecture of these nanomaterials: we learned new information about the chemical composition of quantum dots, and also how atom alignment inside the dots deviates from that of a perfect crystal.
“Importantly, many more measurements of optical and magnetic properties can be done on the same quantum dots which have undergone the NMR probing.”
The development of the new techniques and all experimental work was carried out by Evgeny Chekhovich in Tartakovskii’s group. Quantum dot samples used in this work have also been fabricated in Sheffield, in the EPSRC National Facility for III-V Semiconductor Technology.
Source: University of Sheffield