Researchers Discover Material That Can Convert Infrared Light To Renewable Energy

Researchers at Bengaluru-based Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR)-- an autonomous institute of Department of Science and Technology (DST), have discovered novel material called single-crystalline scandium nitride (ScN) that can emit, and modulate infrared light with high efficiencies making it useful for solar and thermal energy harvesting and for optical communication devices.  

According to the Union Ministry of Science and Technology, only a few existing materials can serve as hosts for light-matter interactions in the infrared spectral range, albeit with very low efficiencies. The operational spectral range of such materials also does not cover industrially important short wavelength infrared (SWIR) spectral range.

For infrared light applications, intelligent and cutting-edge materials are required which can enable excitation, modulation, and detection at desired spectral range with high efficiencies.

Electromagnetic waves are a renewable energy source used for electricity generation, telecommunication, defence and security technologies, sensors, and healthcare services. Scientists use high-tech methods to manipulate such waves precisely -- in dimensions that are thousands of times smaller than the human hair, using specialised materials. However, not all the wavelengths of light (electromagnetic waves) are easy to utilise, especially infrared light, since it is difficult to detect and modulate.

KC Maurya and co-workers have utilised a scientific phenomenon called polariton excitations that occur in tailored materials when light couples with either the collective free electron oscillations or polar lattice vibrations to achieve this feat. They have carefully controlled material properties to excite polaritons (a quasi-particle) and achieve strong light-matter interactions in single-crystalline scandium nitride (ScN) using infrared light.

These exotic polaritons in the ScN can be utilised for solar and thermal energy harvesting. Also, belonging to the same family of materials as gallium nitride (GaN), scandium nitride is compatible with modern complementary-metal-oxide-semiconductor (CMOS) or Si-chip technology and, therefore, could be easily integrated for on-chip optical communication devices.

“From electronics-to-healthcare, defense and security-to-energy technologies, there is a great demand for infrared sources, emitters and sensors. Our work on infrared polaritons in scandium nitride will enable its applications in many such devices,” said Dr. Bivas Saha, Assistant Professor at JNCASR.

Apart from JNCASR, researchers from the Centre for Nano Science and Engineering from the Indian Institute of Science (IISc.) and the University of Sydney also participated in this study published recently in the scientific journal Nano Letters. 

Renewable Energy In India

With the increased support of Government and improved economics, the renewable energy sector has become attractive from an investors perspective. As India looks to meet its energy demand on its own, which is expected to reach 15,820 TWh by 2040, renewable energy is set to play an important role. The government plans to establish renewable energy capacity of 523 GW (including 73 GW from Hydro) by 2030.

As of January 2022, India’s installed renewable energy capacity stood at 152.36 GW, representing 38.56 per cent of the overall installed power capacity. 975.60 MW of renewable energy capacity was added in January 2022. Power generation from renewable energy sources stood at 13.15 billion units (BU) in January 2022, up from 11.51 BU in January 2021.

The country is targeting about 450 Gigawatt (GW) of installed renewable energy capacity by 2030 – about 280 GW (over 60 per cent) is expected from solar. The renewable energy capacity addition stood at 8.2 GW for the first eight months of FY22 against 3.4 GW for the first eight months of FY21. ICRA expects renewable energy capacity addition of 12.5 GW in FY22 and 16 GW in FY23.