Using a hetero-epitaxial lateral overgrowth (ELO) technology with low-temperature deposited AlN interlayer, high-quality crack-free Al 0.22 Ga 0.78 N with low dislocation density is realized. The dislocation density in the Al 0.22 Ga 0.78 N was reduced to as low as the order of 10 7 cm --2 over the whole wafer. Applying the high-quality AlGaN layer to a UV light-emitting diode (LED), high output power of more than 0.1 mW at a forward current of 50 mA has been demonstrated with the emission peak wavelengths from 323 to 352 nm. The highest output power of 0.6 mW is obtained for the 352 nm LED with GaN/AlGaN multiple quantum well active layer. The emission efficiency was dependent on the wavelength, and the 323 nm LED has the lowest output power of 0.18 mW at 50 mA bias. One of the factors determining the external quantum efficiency is thought to be an inferior hole spread in highly resistive p-type layers.
We demonstrated a UV-light-emitting diode on low-dislocation-density AlGaN. This new UV-light-emitting diode shows a peak wavelength of 363 nm, a full-width at half maximum as narrow as 4.8 nm ($45 meV) and an output power of 3.2 mW at 100 mA DC current injection.
The effect of the non-radiative recombination center at or around the dislocations on the performance of the AlGaN-based UV light emitting diode (LED) is discussed. For high-efficiency emission, it is necessary to reduce the density of dislocations to less than 5 × 10 7 cm −2 .
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.