Tiny GaN LEDs assembled into 128 x 96 array
Current power levels are about 0.1 mW per element with an operating voltage of about 3.5 V. To date the researchers have made arrays that emit blue light at 470 nm and have constructed a prototype alphanumeric monochrome microdisplay. According to project leader Martin Dawson, there is potential to extend this to full color operation by adding a polymer or phosphor material on top of selected elements to shift their emission wavelength.
As well as being some 25 times smaller than conventional LEDs, micro-LEDs offer several benefits over their larger counterparts. "They are more efficient and have operating speeds of a few hundred picoseconds," said Dawson. "The array is also a multi-element device where the emitters can be controlled independently. Conventional LEDs are a single-element emitter technology."
The researchers are also using their technology to excite organic materials with fluorescent markings. "This is potentially a very compact and quick way to analyse multiple DNA samples," said Dawson. "Instead of scanning one laser source over the samples, you can use a 2D multi-element emitter source to read the information simultaneously."
Dawson and colleagues are now developing 370 nm (violet) and 540 nm (green) devices, and hope to commercialize the technology in 2-3 years.
