IIT Madras researchers design white light emitters for LED applications

Researchers from the Institute of Technology (IIT), Madras have successfully developed a white light emitter that  can be used in LEDs applications. According to the team, as conventional light-emitting diode (LED) materials cannot emit 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 researchers plan to produce LEDs using their distorted ‘perovskite’ materials. The indigenously-developed bright white light emitters can potentially replace the conventional high-cost materials and phenomenally save the energy cost per lumens.

The innovation has been patented by the researchers and was recently granted the ”SERB-Technology Translation Award”. The Science and Engineering Research Board (SERB) provides financial assistance to researchers, academic institutions, research and development laboratories, industrial concerns, and other agencies.

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.

”While LEDs have been available in almost all colours, white LEDs are a more recent development. Conventional LED materials cannot emit white light and specialized 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,” said Aravind Kumar Chandiran, Assistant Professor, Department of Chemical Engineering, IIT Madras.

The team proposes to use the grant money of Rs 30 lakh to produce LEDs using their distorted perovskite materials. ”The indigenously-developed bright white light emitters can potentially replace the conventional high-cost materials and phenomenally save the energy cost per lumens. We hope to become a technology leader in light emitters in the near future,” added Chandiran.

In their Communications Materials Research 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 strategic introduction of distortion in halide perovskite generated intense light covering the complete visible spectrum. These materials show at least eight times intense white light emission compared to the conventional and well-known Ce:YAG emitters,” said Chandiran.