Improvement of peak quantum efficiency and efficiency droop in III-nitride visible light-emitting diodes with an InAlN electron-blocking layer

InAlN electron-blocking layers (EBLs) are shown to improve the emission intensity and to mitigate the efficiency droop problem in III-nitride-based visible light-emitting diodes (LEDs). Using an $In0.18Al0.82N$ EBL in blue LEDs, we have achieved a significant improvement in the electroluminescence emission intensity and a mitigated efficiency droop compared to similar LEDs without an EBL or with an $Al0.2Ga0.8N$ EBL. This indicates that an $In0.18Al0.82N$ EBL is more effective in electron confinement and reduces the efficiency droop possibly caused by carrier spill-over than conventional AlGaN EBLs.