The reduction of efficiency droop by Al0.82In0.18N/GaN superlattice electron blocking layer in (0001) oriented GaN-based light emitting diodes
<Abstrate>
To investigate the effect of Al0.82In0.18N electron blocking layer (EBL)
on the efficiency droop, (0001) oriented InGaNlight emitting diodes(LEDs)
were grown with two different types of EBLs—single Al0.82In0.18N:Mg
layer and Al0.82In0.18N:Mg (2 nm)/GaN:Mg (2 nm) superlattice(SL)
structure with 7 periods. It was found that the output power and operating
voltage of single Al0.82In0.18N EBL LED were sensitive to EBL thickness
due to the difficulty in growing high quality MgdopedAl0.82In0.18N. On
the other hand, LED with SL EBL showed no deterioration of optical
power and operating voltage while its efficiency droop (17% at 300 A/cm2)
reduced by more than a half compared to a conventional
Al0.2Ga0.8N (20 nm) EBL LED (36% at 300 A/cm2).