IIT-M researchers develop white light emitter for use in LEDs

Researchers at the Indian Institute of Technology-Madras (IIT-M) have successfully developed a white light emitter for use in LEDs which replaced the energy-inefficient incandescent lamps in lighting and display applications.

Conventional LED materials cannot emit white light and specialised techniques such as coating blue LED with yellow phosphor and combining blue, green, and red LEDs, have been used to produce white light.

There has been a worldwide search for materials that can directly emit white light rather than through these indirect techniques that can cause loss of efficiency, the institute said.

The innovation has been patented by the researchers and was recently granted the Government of India’s ‘SERB-Technology Translation Award.’

The research was led by Dr Aravind Kumar Chandiran, Assistant Professor, Department of Chemical Engineering, IIT Madras, and Prof. Ranjit Kumar Nanda B., Department of Physics, IIT Madras.

Apart from the patent, the results of this research work have been published in the prestigious peer-reviewed International journal belonging to the Nature group – Communications Materials.

“The indigenously-developed bright white light emitters can potentially replace the conventional high-cost materials and phenomenally save the energy cost per lumens,” Dr Aravind Kumar Chandiran said.

In their paper, the researchers, in addition to reporting the details of the specific perovskite material, have also proposed a clear design strategy that scientists can employ to develop white light emitters.

The researchers developed expertise in tuning the material at an atomic level to obtain different properties. Through a recent project that included simulation and experimental work, the team distorted the crystal structure of this material to obtain a natural white light emitter, the IIT-M said.

Unlike other recently developed white LED materials, this distorted perovskite 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 IIT-M said.

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