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GaN/GaInN asymmetric multiple quantum well light-emitting diodes with varying potential barrier thicknesses (5 and 15 nm) are grown by using metal organic chemical vapor deposition. The narrow barrier structure improves the performance of the device, including the super-linear increase of electroluminescence integral intensity, the mitigation of efficiency droop at high current density, the reduction of wavelength drift, the reduction of forward voltage, and the improvement of wall-plug efficiency. This is due to the narrowing of the thickness of the quantum barrier, which results in the smaller electric field among the quantum well, the weakening of the quantum confinement Stark effect, the more uniform distribution of carriers across the active region of the device, and the suppression of electron leakage.

Compared with conventional InGaN Quantum Wells (QWs), staggered InGaN QWs offer improved optical and electronic properties. This work studied the carrier concentration, band structure, overlap of hole and electron wave functions, and polarization field of three-layer staggered QWs in the blue spectral region and analyzed them in detail theoretically to explore the source and the dominant mechanism for improvement. Although theoretical studies indicate that the polarization field in QWs of staggered InGaN QWs is larger, the carrier confinement effect is stronger, and the carrier distribution is more uniform. Therefore, three-layer staggered QWs can improve overlapping of the hole and electron wave functions and then enhance the recombination rate so as to increase the optical output power and electroluminescence intensity. Moreover, the performance of the staggered structure C with the lowest indium content at the center of the well is better than that of the step-staggered structure B.