White LEDs drastically reduced energy consumption of light. But they still can be produced cheaper and in a more sustainable way, according to Maryna Meretska of the University of Twente. She wants to develop LEDs that emit more light while for their production, less phosphor is needed. For research on the M-White LED she proposes, she now gets the opportunity to go to Harvard University for two years. For this, she received a Rubicon grant of NWO, the Netherlands Organisation for Scientific Research.
Since the Nobel Prize winning invention of the blue LED, an energy efficient white LED could be developed as well. Our lighting systems occupy a third position in energy consumption. Using LEDs, this can be reduced. Another advantage is that light sources come within reach of more people worldwide, also in countries with limited energy supply.
For LEDs, there is a law that resembles the well-known Moore’s Law for semiconductors. ‘Haitz’s Law’ predicts the prize of LEDs, per lumen, goes down by a factor 10 every ten years while the amount of emitted light goes up with a factor 20. This law is reaching it limits, but Maryna Meretska sees opportunities for pushing these limits. She recently defended her PhD thesis title ‘Taming a white LED’ and is going to develop a ‘meta white LED’ (M-White LED) that is suitable for all lighting applications and of which the colour can be tuned better. For this new LED, far less phosphor is needed, she predicts: half or even less.
Meretska will work on her ideas in the group of Prof Federico Capasso of Harvard University. This group did pioneering work on surface properties of new optical devices. For doing research at Harvard, Meretska received a Rubicon grant of the Netherlands Organisation for Scientific Research.
Maryna Meretska is with the UT group Complex Photonic Systems (MESA+ Institute for Nanotechnology). She defended her PhD thesis on 23 February. A recent publication of her work was in Optics Express: see press release ‘Tracing the light inside LEDs’.