Increasing the internal quantum efficiency of green GaN-based light-emitting diodes by employing graded quantum well and electron blocking layer

By numerical investigation of various structures, we have proposed a promising single quantum well device for efficient green InGaN-based light-emitting diodes. The peak internal quantum efficiency of the proposed structure, at lower current density, is enhanced and shows significant droop reduction at high current density. The efficiency droop ratio of the proposed structure is similar to 31% at 100 A cm(-2). Similarly, the light output power is also doubled as compared to conventional light-emitting diode. In the proposed structure, the simultaneously graded quantum well and electron blocking layer are employed. Therefore, the injection of holes into the active region becomes easier due to graded electron blocking layer and radiative recombination is boosted due to graded quantum well. By implement the proposed structure, both the problem of injection of holes and separation of electron-hole wavefunctions are greatly reduced.