Improvement in piezoelectric effect of violet InGaN laser diodes

The laser performance of violet InGaN laser diodes is investigated numerically. The polarization-dependent properties, including overlap of electron and hole wavefunctions, threshold current, and slope efficiency, are studied through the use of step-like quantum well structure. Furthermore, the electron and hole wavefunctions, band diagrams, and emission wavelength are compared and analyzed. The simulation results show that the lowest threshold current and the highest slope efficiency are obtained when the step-like quantum well structure is designed as In_0.12Ga_0.88N (2.5 nm)-In_0.18Ga_0.82N (1 nm) or In_0.18Ga_0.82N (2.5 nm)-In_0.12Ga_0.88N (1 nm) for violet laser diodes due to sufficiently enhanced overlap of electron and hole wavefunctions.