Scientists have discovered a new material that can efficiently emit, detect, and modulate infrared light, making it useful for solar and thermal energy harvesting as well as optical communication devices. Electromagnetic waves are a renewable energy source that is used in the generation of electricity, telecommunications, defence and security technologies, sensors, and healthcare services.
Scientists use high-tech methods to precisely manipulate such waves in dimensions thousands of times smaller than a human hair, using specialized materials. However, not all light wavelengths (electromagnetic waves) are easily utilized, particularly infrared light, which is difficult to detect and modulate.
Intelligent and cutting-edge materials that can enable excitation, modulation, and detection at desired spectral ranges with high efficiencies are required for infrared light applications. Only a few existing materials, with very low efficiencies, can serve as hosts for light-matter interactions in the infrared spectral range. Such materials' operational spectral range also excludes the industrially important short-wavelength infrared (SWIR) spectral range.
Researchers from the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) in Bengaluru, an autonomous institute of the Department of Science and Technology (DST), have discovered a novel material called single-crystalline scandium nitride (ScN) that can emit, detect, and modulate infrared light with high efficiencies.
To accomplish this feat, K. C. Maurya and colleagues used polariton excitations, which occur in tailored materials when light couples with either collective free electron oscillations or polar lattice vibrations. They used infrared light to excite polaritons (a type of quasi-particle) and achieve strong light-matter interactions in single-crystalline scandium nitride (ScN).
These exotic polaritons in ScN can be used to harvest solar and thermal energy. Scandium nitride, which belongs to the same material family as gallium nitride (GaN), is also compatible with modern complementary-metal-oxide-semiconductor (CMOS) or Si-chip technology and thus could be easily integrated for on-chip optical communication devices.
"From electronics to healthcare, defence and security to energy technologies, infrared sources, emitters, and sensors are in high demand." "Our research on infrared polaritons in scandium nitride will enable its use in a variety of such devices," said Dr. Bivas Saha, Assistant Professor at JNCASR. Aside from JNCASR, researchers from the Indian Institute of Science (IISc.) and the University of Sydney also took part in this study, which was recently published in the scientific journal Nano Letters.
