Power-enhanced ITO omni-directional reflective AlGaInP LEDs by two-dimensional wavelike surface texturing

Abstract

An n-side up-type AlGaInP multiple-quantum-well light-emitting diode (LED) has been developed by texturing the current spreading layer utilizing photolithography followed by an anisotropic etching process over n-AlGaInP grown by metalorganic chemical vapor deposition. The GaP-ITO-Ag omni-directional reflective LEDs with the wavelike textured surfaces provide a reasonable improvement in light output power and efficiency over the corresponding conventional structures. The luminous intensity of the surface-textured LED is 1.46 times greater than that of the conventional LED in the normal direction. The output power (at 350 mA) of the surface-textured LED is increased approximately 40% as compared with that of the conventional LED. Additionally, the optical simulation also presents a tendency towards the ray extraction ratio as the size of the wavelike hole changes, confirming a proper formation of pattern size associated with the fabrication process.