Enhancing the performance of GaN based LDs by using low In content InGaN instead of GaN as lower waveguide layer. (April 2019) - Yang, J.
Highlights: Threshold current of LD decreases when InGaN instead of GaN is used as low waveguide layer. The In content of InGaN low waveguide layer must be low. The quality of InGaN layer decreases with increasing the In content of InGaN layer. Abstract: Performance of InGaN based blue laser diodes (LDs) with different In content of (In)GaN lower waveguide (LWG) layers are investigated by simulation and experimental methods. It is found from the simulation results that the threshold current decreases and slope efficiency increases when the In content of InGaN LWG layer increases from 0% to 6%. However, when the In content is too high, the optical confinement factor of MQWs decreases, recombination rate in LWG layer increases and the surface morphology becomes roughness, all of these result in the deterioration of the performance of LDs with high In content InGaN LWG layer, the output power decreases from 97 to 83 mW at the injection current of 100 mA. It agrees well with the experiment results that the performance of LDs can be improved by using a low In content InGaN instead of GaN as lower waveguide layer.