MOSCOW, May 10. /TASS/. Skoltech Professor Athanasios Polimeridis and his colleagues from Princeton University demonstrated that thermal radiation of the nanostructures can be readily tailored by changing their geometry, Skoltech press service said on Tuesday.
Controllable thermal radiation has enabled unprecedented advances in important technological areas. "The ability to tune the radiation properties of composite nanostructures offers potentially new applications in nanophotonics and nanoelectronics, including photovoltaics, energy storage, incoherent sources, and detection," Skoltech said.
Understanding of quantum behavior of materials is of utmost importance for modern electronics. Quantum effects become increasingly influential as the feature size decreases to the wavelength-scale. Novel materials with dramatically different optical properties than those observed in nature can be created when understanding of the nature and peculiarities of quantum effects is applied. To date, radiation patterns from wavelength-scale composite structures have not been explored.
Polimeridis with colleagues are studying light-matter interactions in nanostructured media with features on the scale of electromagnetic wavelength. In a recent Rapid Communication in Physical Review B they address the problem of thermal radiation from the nanoemitters. In this work, the researchers exploit a recently proposed fluctuating-volume current (FVC) formulation of electromagnetic fluctuations to show that wavelength-scale composite objects can demonstrate designable, directional emission at infrared wavelengths,
The researchers showed that micro-scale chalcogenide hemispheroids coated with titanium or silicon-nitride shells and resting on transparent substrates can exhibit large emissivity and >80% partial directivity. They also demonstrated that temperature localization, shape and material dispersion within the composite objects are important to achieve directional emission, and therefore simultaneous design of electromagnetic scattering and thermal properties of structures is required.
Professor Polimeridis and his colleagues see the proposed approach, which combines both nanophotonic and conductive design principles, is poised to take advantage of temperature management and heat transport at submicron scales.