Molecular beam epitaxial growth, fabrication, and characterization of high efficiency InGaN/GaN Dot-in-a-wire white light emitting diodes on Si(111)

We report on the molecular beam epitaxial growth, fabrication, and characterization of InGaN/GaN dot-in-a-wire white light emitting diodes (LEDs) grown on Si(111). By varying the In compositions in the dot layers, we have demonstrated strong white light emission. The dot-in-a-wire LEDs exhibit a relatively high internal quantum efficiency of ∼ 36.7% and virtually zero efficiency droop for current densities up to ∼ 200 A/cm² at room temperature, which are attributed to the superior 3-dimensional carrier confinement provided by the dots and to the use of nearly defect and strain-free GaN nanowires.