Enhanced light extraction from GaN-based green light-emitting diode with photonic crystal

This letter reports the properties of GaN-based green light-emitting diodes (LEDs) having a p-GaN photonic crystal layer with a photonic bandgap (PCWG) and without a photonic bandgap (PCOG). With decreasing the photoluminescence (PL) detection angle from 140° to 60°, the enhancement of PL intensity of LED with PCWG was largely increased from 9 to 25 times, compared to that of LEDs without a patterned structure, while the PL intensity of LED with PCOG was increased from 4.6 to 5.6 times. The electroluminescence output power of green LEDs with a PCWG was enhanced about two times compared to LEDs with a PCOG. These results suggest that the light extraction of green LEDs can be greatly increased by using PCWG instead of PCOG.