Exploring efficiency limits of red GaN micro-LEDs

GaN micro-LEDs are expected to revolutionize display technology offering applications in, e.g., virtual reality displays and mobile phones.

Compared to currently used liquid crystal and organic LED displays, GaN micro-LEDs offer much higher luminance and lower energy consumption.

However, for efficient GaN RGB displays, a substantial increase of red micro-LED efficiency is required.In this project we aim at understanding physical phenomena that limit efficiency of red GaN micro-LEDs and suggest ways for its improvement at least three-fold.

We will perform studies of carrier recombination, transport, and thermal effects on standard and custom-designed micro-LEDs using unique multimode scanning near-field optical microscopy technique, which allows simultaneous mapping of emission spectra, carrier recombination times, and surface temperature, all with ~100 nm spatial resolution.

We will concentrate on effects specific to red micro-LEDs, such as carrier recombination via surface states, interwell transport and novel carrier injection schemes.

Since none of such studies have been performed before, the project will provide new knowledge, which should lead to a disruptive improvement of GaN micro-LED technology. The project is foreseen for three years and will be conducted by a postdoctoral researcher and the applicant.

It will be run in close collaboration with the GaN group from University of California, Santa Barbara, who will provide research samples and expertise in micro-LEDs.