Physicists suggest reversible adjustment of nanoparticles emission colour

August 16, 2018, ITMO University
Restructuring of nanoparticle emission spectrum. Credit: ITMO University

Researchers have found a method of reversibly adjusting the radiation color of nanosized light sources. Previously, radiation color could be specified only during nanoparticle synthesis, but now it can be changed after synthesis. Stability and electromagnetic resonances of the particles are retained during this adjustment. This makes them promising for optical chips, LEDs and optoelectronic devices. The results are published in Nano Letters.

Resonance is the coincidence between frequencies of two oscillations increasing their intensity. A half-century ago, the Italian theoretical physicist Hugo Fano described a special type of resonance with an asymmetric profile arising from the interference of two wave processes. Since then, Fano resonance has been actively used in photonics, for example, to create fast optical switches, which are elements of . The reduction of such switches to nanoscale will dramatically increase the performance of photonic chips by integrating a huge number of elements in one device.

Researchers from ITMO University, together with colleagues from Sweden, Australia, the United States and Lithuania, have discovered Fano resonance in perovskite nanoparticles and gained control over the resonance spectrum for an array of inorganic nanoparticles. To do this, they proposed a new method of tuning the radiation of nanoparticles. Instead of synthesizing several types of particles, they proposed changing the composition of one ready particle through special chemical treatment. As this adjustment is reversible, it can be repeated many times without changing the stability of the particles and the intensity of their radiation.

"We conducted experiments with single organo-inorganic perovskite nanoparticles, as well as with an unordered array of completely inorganic nanoparticles dispersed in the polymer matrix. We managed to register Fano resonances in both cases, but the reversible tuning was possible only for inorganic particles. They include bromine anions, and during the adjustment, we reversibly changed the bromine atoms to the chlorine atoms. This makes it possible to shift the of particles in the range of 420-520 nm. Organo-inorganic nanoparticles proved to be unsuitable for a similar adjustment of photophysical properties due to the presence of organic cations in their structure," says Anatoly Pushkarev, research associate at the Laboratory of Hybrid Nanophotonics and Optoelectronics of ITMO University.

According to the researchers, the proposed method for tuning the emission spectrum of perovskite nano-antennas is universal. It can be applied to other inorganic nanostructures based on lead halides. Thus, it is possible to obtain complex on a chip with the minimum amount of nanoparticles. Such miniature devices can serve for data transmission and processing, as well as for sensing.

"The results we obtained are promising not only for the creation of photonic integrated circuits. The reconstruction of the emission spectrum of the array and the change in the position of the Fano in their optical absorption spectrum can be used, for example, to determine the concentration of hydrogen halide vapor (HCl, HBr, HI) in the medium," says Ekaterina Tiguntseva, a graduate student of the Faculty of Physics and Technology of ITMO University.

Explore further: Researchers invent light-emitting nanoantennas

More information: Ekaterina Y. Tiguntseva et al. Tunable Hybrid Fano Resonances in Halide Perovskite Nanoparticles, Nano Letters (2018). DOI: 10.1021/acs.nanolett.8b01912

Related Stories

Researchers invent light-emitting nanoantennas

February 19, 2018

Scientists from ITMO University have developed effective nanoscale light sources based on halide perovskite. Such nanosources are based on subwavelength nanoparticles serving both as emitters and nanoantennas and allow enhancing ...

A silicon-nanoparticlephotonic waveguide

July 16, 2018

A new way to efficiently guide light at tiny scales has been demonstrated by an all-A*STAR team. Their method, which involves lining up silicon nanoparticles, is promising for applications such as light-based integrated circuits, ...

Nanodiamond turns into controllable light source

May 2, 2018

A research group from ITMO University has developed a controlled light source based on nanodiamond. Experiments have shown that the diamond shell doubles the emission speed light sources and helps to control them without ...

Recommended for you

In colliding galaxies, a pipsqueak shines bright

February 20, 2019

In the nearby Whirlpool galaxy and its companion galaxy, M51b, two supermassive black holes heat up and devour surrounding material. These two monsters should be the most luminous X-ray sources in sight, but a new study using ...

Research reveals why the zebra got its stripes

February 20, 2019

Why do zebras have stripes? A study published in PLOS ONE today takes us another step closer to answering this puzzling question and to understanding how stripes actually work.

When does one of the central ideas in economics work?

February 20, 2019

The concept of equilibrium is one of the most central ideas in economics. It is one of the core assumptions in the vast majority of economic models, including models used by policymakers on issues ranging from monetary policy ...

Correlated nucleons may solve 35-year-old mystery

February 20, 2019

A careful re-analysis of data taken at the Department of Energy's Thomas Jefferson National Accelerator Facility has revealed a possible link between correlated protons and neutrons in the nucleus and a 35-year-old mystery. ...


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.