Pulsed Atomic Layer Epitaxy of Quaternary AlInGaN Layers for Ultraviolet Light Emitters

Abstract

We report on a pulsed atomic layer epitaxy (PALE) technique for quaternary AlInGaN growth. PALE allows for the deposition of high-quality AlInGaN layers at much lower temperatures than those required for conventional low-pressure metalorganic chemical vapor deposition (MOCVD). The low growth temperature leads to an efficient incorporation of indium and, as a result, to a dramatic improvement in emission properties of the material. A deep ultraviolet optical gain of 300 cm -1 peaked at 330 nm is obtained in quaternary AlInGaN MQWs. Also, in PALE AlInGaN material, the optical emission properties do not degrade with increasing Al mole fraction. These results establish PALE as a promising technique for deep UV emitters.