Circa 2018
Researchers have demonstrated nanomaterial-based white-light-emitting diodes (LEDs) that exhibit a record luminous efficiency of 105 lumens per watt. Luminous efficiency is a measure of how well a light source uses power to generate light. With further development, the new LEDs could reach efficiencies over 200 lumens per watt, making them a promising energy-efficient lighting source for homes, offices and televisions.
“Efficient LEDs have strong potential for saving energy and protecting the environment,” said research leader Sedat Nizamoglu, Koç University, Turkey. “Replacing conventional lighting sources with LEDs with an efficiency of 200 lumens per watt would decrease the global electricity consumed for lighting by more than half. That reduction is equal to the electricity created by 230 typical 500-megawatt coal plants and would reduce greenhouse gas emissions by 200 million tons.”
The researchers describe how they created the high-efficiency white LEDs in Optica, The Optica l Society’s journal for high impact research. The new LEDs use commercially available blue LEDs combined with flexible lenses filled with a solution of nano-sized semiconductor particles called quantum dots. Light from the blue LED causes the quantum dots to emit green and red, which combines with the blue emission to create white light.