A new technique―the result of an international collaboration of scientists from Lehigh University, West Chester University, Osaka University and the University of Amsterdam―could pave the way for monolithic integration for simple color tuning of a light bulb, according to Volkmar Dierolf, Distinguished Professor and Chair of Lehigh’s Department of Physics, who worked on the project.
“This work could make it possible to tune between bright white and more comfortable warmer colors in commercial LEDs,” says Dierolf.
The team demonstrated the possibility of color tuning Gallium Nitride (GaN)-based GaN LEDs simply by changing the time sequence at which the operation current is provided to the device. Light-emitting diodes or LEDs are semiconductor devices that emit light when an electric current is passed through it. Notably, the technique is compatible with current LEDs that are at the core of commercial solid state LED lighting.
The work is described in an article published online in ACS Photonics called “Color-Tunablility in GaN LEDs Based on Atomic Emission Manipulation under Current Injection.” The lead author, Brandon Mitchell, is a former graduate student in Dierolf’s lab and now an assistant professor in the Department of Physics and Engineering at West Chester University in Pennsylvania.
In today’s active LED displays, different colors are produced by three to four individual LEDs that are placed close to each other and create the different fundamental colors needed to produce the full color spectrum.