Growth and characterization of AlGaInN for UV optoelectronics

Several issues related to the growth of nitride-based UV light emitters will be discussed in this work. In contrast to the widely pursued, InGaN-based, blue LEDs, UV LEDs mandates the use of an active layer of little or no indium. To provide comparable level of electrical and optical confinement, one has to employ ternary AlGaN with a higher fraction of Al and an increased thickness. Two issues which will be addressed in the talk, therefore, are the role of indium in GaN:In and AlGaN:In heterostructures for UV emission, and the control of grown-in strain (due to tensile mismatch between AlGaN and GaN) using a compliant interlayer to avoid cracking. Finally, we will summarize the results of various exploratory UV optoelectronic devices.