The effect of the band-offset ratio on the characteristics of the blue InGaN quantum-well lasers is studied numerically. Specifically, the optical properties are investigated when the band-off ratio of the InxGa1-xN/InyGa1-yN heterojunction is 7/3. Simulation results indicate that the laser performance is better for a blue laser diode with a band-offset ratio of 7/3 than for one with a band-offset ratio of 3/7. Moreover, the problem of non-uniform hole distribution in the blue InGaN quantum-well lasers becomes less severe, and the non-uniform electron distribution becomes more obvious when the band-offset ratio is changed from 3/7 to 7/3. The lowest threshold current is obtained when the number of InGaN well layers is one when the band-offset ratio is 7/3.
