The influence of the (In)GaN quantum barrier growth temperature on the structural properties of the active region of blue-violet laser diodes has been investigated. Therefore, multiple quantum well structures were prepared by metal-organic vapor phase epitaxy, with (In)GaN barriers grown either at the same temperature as the InGaN quantum wells, or at a GO K higher growth temperature. A GO K higher growth temperature results in smoother quantum barrier layers with fewer defects on a microscopic scale, as revealed by scanning electron microscopy and cathodoluminescence studies. On the other hand samples with a 0 K offset showed a higher strain in the quantum wells determined by X-ray diffraction and a narrower photoluminescence emission spectra. Secondly, laser heterostructures with InGaN barriers were prepared for optical pumping using different growth schemes. The laser structure with the active region deposited with a 0 K offset exhibits significantly lower optical threshold power densities of around 200 kW/cm(2) compared to 700 kW/cm(2) for the GO K offset sample. Also, transmission electron microscopy revealed quantum wells with improved lateral uniformity in the samples grown without temperature offset. Based on these results, a current-injection broad area laser diode with an active region growth scheme without temperature offset was prepared on (0001) GaN substrate. The diode emits around 420 am with a threshold current density of around 1.6 kA/cm, (C) 2014 Elsevier B.V. All rights reserved,