Improved characteristics of InGaN multi-quantum-well laser diodes grown onlaterally epitaxially overgrown GaN on sapphire

InGaN multi-quantum-well laser diodes have been fabricated on fully-coalesc ed laterally epitaxially overgrown (LEO) GaN on sapphire. The laterally ove rgrown 'wing' regions as well as the coalescence fronts contained few or no threading dislocations. Laser diodes fabricated on the low-dislocation-den sity wing regions showed a reduction in threshold current density from 8 kA /cm2 to 3.7 kA/cm2 compared the those on the high-dislocation 'window' regi ons. Laser diodes also showed a twofold reduction in threshold current dens ity when comparing those on the wing regions to those fabricated on convent ional planar GaN on sapphire. The internal quantum efficiency also improved from 3% for laser diodes on conventional GaN on sapphire to 22% for laser diodes on LEO GaN on sapphire.