A new method for studying semiconductor nanoparticles has been tested

May 16, 2018, Siberian Federal University

A team from Siberian Federal University and Kirensky Institute of Physics (Siberian Department of the Russian Academy of Sciences) has developed a new method to study nanoparticles made of cadmium telluride (CdTe). The compound's peculiar interaction with light differs depending on the magnetic field. The results of the study were published in the Physics Letters A journal.

The interaction of certain substances with electromagnetic radiation depends on the magnetic characteristics of the environment. In particular, the magnetic circular dichroism effect can play a role. When this phenomenon is present, the absorption of light with different circular polarizations differs if it moves along the direction of magnetization. Magnetization may be determined by the properties of the substance itself (in the case of ferromagnetic materials) or by the influence of an .

The physicists of Siberian Federal University are making structures from colloidal (suspended in medium, in this case, in water) quantum dots. "Due to the tiny size of these objects (quantum dots are about three nanometers in diameter) the final structures are also quite small," explains co-author Alexey Tsipotan. "After the experiments are over and structures are formed, they need to be studied—for instance, using electron microscopy or light spectroscopy. However, in the case of electron microscopy, first of all, the object should be deposited on a surface, which may cause the to change."

In the course of a search for the new method, the scientists suggested using the magneto-optic effect to study the structures without making any additional modifications. The colloidal nanoparticles in question seemed to have the magnetic circular dichroism effect. Therefore, methods based on it could be used for studying the forming structures. Cadmium telluride particles don't possess magnetism themselves, and the effect is observed only under the influence of an external magnetic field.

"The potential range of use of is extremely wide," concluded Tsipotan. "Most notably, they are excellent luminophores—their quantum yield of luminescence is on the same level as in dyes, but they are more photostable, i.e. they don't fade away under the influence of sunlight. Due to this property they may be used as light-emitting elements of optical diodes. Also, they may be used in solar cells for more efficient sunlight transformation. Another area of their potential application is biology where dots may be used as markers. Moreover, Samsung has recently launched a TV set in which are added to light-emitting diodes."

Explore further: Scientists roll 2-D cadmium telluride into nanoscrolls

More information: A.V. Malakhovskii et al, Magnetic circular dichroism of CdTe nanoparticles, Physics Letters A (2018). DOI: 10.1016/j.physleta.2018.02.012

Related Stories

Scientists roll 2-D cadmium telluride into nanoscrolls

April 24, 2018

A team of scientists from the Faculty of Chemistry and the Faculty of Materials Science, MSU, together with foreign colleagues, discovered that two-dimensional sheets of cadmium telluride can spontaneously fold into nanoscrolls. ...

Gold changes photoluminescence of silicon quantum dots

April 9, 2018

A group of scientists from Russia and Sweden showed that applying gold stripes to a sample with silicon quantum dots modifies the dots' properties. Their study results were published in Scientific Reports.

Optical nanoscope images quantum dots

January 23, 2018

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together ...

Making quantum dots glow brighter

September 16, 2014

Researchers from the University of Alabama in Huntsville and the University of Oklahoma have found a new way to control the properties of quantum dots, those tiny chunks of semiconductor material that glow different colors ...

Recommended for you

Magnesium magnificent for plasmonic applications

May 22, 2018

Rice University researchers have synthesized and isolated plasmonic magnesium nanoparticles that show all the promise of their gold, silver and aluminum cousins with none of the drawbacks.

Valves for tiny particles

May 22, 2018

Newly developed nanovalves allow the flow of individual nanoparticles in liquids to be controlled in tiny channels. This is of interest for lab-on-a-chip applications such as in materials science and biomedicine.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.