III-Nitride Nanostructures for High Efficiency Micro-LEDs and Ultraviolet Optoelectronics

Microscale visible light emitting diodes (LEDs), as well as LEDs and laser diodes operating in the mid and deep ultraviolet (UV), have emerged as the frontier of semiconductor optoelectronics and are poised to revolutionize mobile displays, virtual/augmented reality, water purification, sterilization, and many other critical applications. In this article, we provide an overview of some recent developments of III-nitride nanostructures by molecular beam epitaxy and their applications in micro-LEDs and deep UV optoelectronics including LEDs and laser diodes. Due to the efficient surface strain relaxation, III-nitride nanostructures exhibit significantly reduced dislocation densities compared to their conventional quantum well counterparts. Studies have further shown that p-type Mg-dopant incorporation is much more efficient in nanostructures. These attributes have been exploited to realize high efficiency micro-LEDs operating in the deep visible (e.g., green and red) and to achieve relatively efficient LEDs operating in the UV-C and far UV-C spectra. The utilization of III-nitride nanostructures to realize electrically injected laser diodes with relatively low threshold is also presented.