Commercial uses for ultraviolet (UV) light are growing, and now a new kind of LED under development at The Ohio State University could lead to more portable and low-cost uses of the technology.
The patent-pending LED creates a more precise wavelength of UV light than today’s commercially available UV LEDs, and runs at much lower voltages and is more compact than other experimental methods for creating precise wavelength UV light.
The LED could lend itself to applications for chemical detection, disinfection, and UV curing. With significant further development, it might someday be able to provide a source for UV lasers for eye surgery and computer chip manufacture.
In the journal Applied Physics Letters, Ohio State engineers describe how they created LEDs out of semiconductor nanowires which were doped with the rare earth element gadolinium.
The unique design enabled the engineers to excite the rare earth metal by passing electricity through the nanowires, said study co-author Roberto Myers, associate professor of materials science and engineering at Ohio State. But his team didn’t set out to make a UV LED.
“As far as we know, nobody had ever driven electrons through gadolinium inside an LED before,” Myers said. “We just wanted to see what would happen.”
When doctoral students Thomas Kent and Santino Carnevale started creating gadolinium-containing LEDs in the lab, they utilized another patent-pending technology they had helped develop—one for creating nanowire LEDs. On a silicon wafer, they tailor the wires’ composition to tune the polarization of the wires and the wavelength, or color, of the light emitted by the LED.
Gadolinium was chosen not to make a good UV LED, but to carry out a simple experiment probing the basic properties of a new material they were studying, called gadolinium nitride. During the course of that original experiment, Kent noticed that sharp emission lines characteristic of the element gadolinium could be controlled with electric current.
Read more at: Phys.org