Efficiency improvement progress in green, yellow and red III-Nitride LEDs

Widening the range of efficiently emitting wavelengths is a goal of ongoing research on III-nitride LEDs. The so-called green gap is mainly related to the increasing severity of efficiency droop as the wavelength increases. The peak EQE in commercial green LEDs exceeds 60% but corresponds to a very low current density. In this presentation we review challenges in the development of long wavelength III-nitride LEDs. We discuss possible strategies to mitigate droop based on the understanding that nonradiative Auger recombination is the root cause. Finally, we present the current efficiency status of green, yellow and red III-Nitride LEDs.