Effects of electronic current overflow and inhomogeneous carrier distribution on InGaN quantum-well laser performance

Laser performance of several InGaN quantum-well (QW) lasers with an emission wavelength of 392-461 nm are numerically studied with a LASTIP simulation program. Specifically, the effects of electronic current overflow and inhomogeneous carrier distribution on the laser performance of InGaN QW lasers operating at different wavelengths are investigated. Simulation results indicate that the use of an AlGaN blocking layer can help reduce the electronic current overflow and, in addition to the dissociation of the InGaN well layer at a high growth temperature during crystal growth, the inhomogeneous carrier distribution in the QWs also plays an important role in the laser performance. From the simulation results, we conclude that the lowest threshold current density is obtained when the number of InGaN well layers is two if the emission wavelength is shorter than 427 nm and one if the emission wavelength is longer than 427 nm, which are in good agreement with the results observed by Nakamura et al. in their experiments.