Researchers at the Indian Institute of Technology Madras (IIT-M) have developed a perovskite-based white light emitter for use in energy-efficient Light Emitting Diodes or LEDs.

As conventional LED materials cannot emit white light, to produce white light, specialized techniques such as coating blue LED with yellow phosphor and combining blue, green, and red LEDs have been used, along with a worldwide search for materials that can directly emit white light.

"The indigenously-developed bright white light emitters can potentially replace the conventional high-cost materials and phenomenally save the energy cost per lumens," said Dr. Aravind Kumar Chandiran, Assistant Professor, Department of Chemical Engineering, IIT Madras.

The team proposed a clear design strategy that scientists can employ to develop white light emitters. The team, which has patented the technology, were also granted the Government of India's 'SERB-Technology Translation Award', which they aim to use to produce LEDs using their distorted perovskite materials.

"We believe that our work contributes to the Government of India's 'Make in India' programme and we hope to become a technology leader in light emitters in the near future," Chandiran said.

The IIT Madras team has been exploring Halide-Perovskites for various applications. In this recent project, the team distorted the crystal structure of the material to obtain a natural white light emitter. This distorted perovskite can be used independently as a white light emitter or as a phosphor in combination with blue LEDs to produce white light.



Unlike other recently developed white LED materials, this distorted perovskite also showed phenomenal stability under ambient conditions. The emission of intense light and stability make them useful in long-lasting, energy-saving lighting applications.

Apart from general lighting, white LEDs can potentially be used in liquid crystal display backlights, display mobile lighting, and medical and communication equipment, the researchers explained.

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