Enhanced light output power of InGaN-based amber LEDs by strain-compensating AlN/AlGaN barriers

•The light output power of the amber LED was enhanced 2.5-fold at 20 mA.•The Al0.03Ga0.97N barrier led to improved crystalline quality of the InGaN 3QWs.•The PL-FWHMs were significantly improved with AlN/Al0.03Ga0.97N barriers.•The strain compensating AlN/AlGaN barrier is very promising for improving the EQE.

We investigated the effect of a combined AlN/Al0.03Ga0.97N barrier on InGaN-based amber light-emitting diodes (LEDs) grown by metalorganic vapor-phase epitaxy. InGaN-based multiple quantum wells with a combined AlN/Al0.03Ga0.97N barrier showed intense photoluminescence with a narrow full-width at half-maximum. The amber LEDs with a combined AlN/Al0.03Ga0.97N barrier achieved a light output power enhanced approximately 2.5-fold at 20 mA compared to that of the LED with a combined AlN/GaN barrier, owing to the reduction of defects in InGaN active layers. Thus, the efficiency of high-In-content InGaN-based LEDs can be improved in the spectrum range of amber.