High-efficiency GaN-based LED with patterned SiO2 current blocking layer deposited on patterned ITO

GaN-based blue light-emitting diodes (LEDs) with patterned SiO2 current blocking layer (CBL) deposited on patterned indium-tin oxide (ITO) transparent conductive layer has been proposed and performed. The patterned SiO2 layer was inserted between ITO and p-/n-electrodes, serving as both CBL and passivation layer. The results showed that the proposed single patterned SiO2 CBL can significantly improve the current spreading and light emission intensity of the fabricated LEDs. Additionally, the ITO with periodic circular patterns underneath p-electrode was formed to enhance scattering events of light emanated from InGaN/GaN active emitting region, leading to a reduced light absorption by opaque p-electrode and improved light extraction efficiency (LEE). As a result, at 200 mA, the external quantum efficiency (EQE) of the LED with patterned SiO2 CBL deposited on patterned ITO was 13.8% higher than that of conventional LED.