Scientists from Russia and France have created quantum dots based on graphene up to several tens of nanometers. This was achieved due to the bombardment of a film of fluorinated graphene by ions of xenon. About their work, the researchers reported in the journal Nanotechnology.
Quantum dot is a semiconductor particle in which the electrons are in a potential well, that is “locked” and unable to freely move around the crystal. Quantum dots find application in medicine and biology as a fluorescent label, in physics and electronics as the basis for single electron transistors and logical elements of a quantum computer, as well as many other places. Computational devices based on quantum dots are usually very sensitive to external noises, therefore, to improve the accuracy of the calculations they are cooled to very low temperatures.
But now researchers from the Institute of semiconductor physics to them. A.V. Rzhanov SB RAS together with Russian and foreign colleagues presented the quantum dot graphene-based devices which can operate at higher temperatures and do not require serious cooling costs. Informed of graphene has created quantum dots. This material is “sliced” into small particles. But when the edges of the resulting fragments, and oxidized the resulting quantum dots was reduced practically important properties, such as conductivity and mobility of charge carriers.
To circumvent this limitation, the authors of new work have decided to create quantum dots-based verografina — normal graphene, some of the atoms connected to the atoms of fluorine. Based on this material, the researchers irradiated with ions of xenon with energies from 26 to 167 MeV. Due to the short and powerful heat generation in time-of-flight ion material forgettably matrix locally expanded and restored to graphene close to the trajectories of the ions. In addition to the synthesis, the researchers proposed a model of the process.
“it seems that radiation destroys the individual particles of fluorinated graphene, which comprises the film. This leads to the formation of small — 20-40 nanometers in diameter — granules with quantum dots. I wonder, then, that the pellets “stick together” into larger spherical formations. We didn’t expect to see a similar process, but was able to observe it in the experiment and confirmed through simulation,” said first author, research fellow, Institute of semiconductor physics to them. A.V. Rzhanov SB RAS Nebogatikova Nadezhda.