Brighter LEDs the promise of new technique
A production method that makes LEDs brighter and more resilient has been heralded by a team from North Carolina State University.
"By coating polar GaN with a self assembling layer of phosphonic groups, we were able to increase luminescence without increasing energy input," noted Ph.D. student Stewart Wilkins. "The phosphonic groups also improve stability, making the GaN less likely to degrade in solution."
The researchers started with polar GaN, which is composed of alternating layers of gallium and nitrogen.To increase luminescence, they etched the surface of the material with phosphoric acid.
At the same time, they added phosphonic groups – organic molecules containing phosphorus – that self-assembled into a monolayer on the surface of the material.
This layer further increased luminescence and improved the stability of the GaN by making it less likely to react chemically with its environment.
The researchers believe the method could make LEDs better suited to biomedical applications such as implantable sensors.
