Ultraviolet laser diodes grown on semipolar (2021) GaN substrates by plasma-assisted molecular beam epitaxy

摘要

We demonstrate ultra-violet laser diodes emitting at 388?nm grown by plasma-assisted molecular beam epitaxy on semipolar (20 style='border-top:solid 1px black;'>21)GaN substrates under metal-rich conditions. The threshold current density and voltage of 13.2?kA/cm2 and 10.8?V were measured at room temperature for devices with the laser ridge waveguide oriented along the [ style='border-top:solid 1px black;'>12 style='border-top:solid 1px black;'>10] direction. We show smooth, atomically flat surface morphology after growth. The excellent structural quality of the laser heterostructure was corroborated by transmission electron microscopy.