Novel High-Radiance Surface-Emitting Light Emitting Diode Structure with Circular 45 degree Corner Reflector and Microlens

Abstract

A new type of light-emitting diode(LED) with a circular 45 degrees corner reflector and microlens is proposed and fabricated. The improvement of light output power of the proposed LED structure is calculated and compared with that of the conventional surface-emitting LED type. A microlens is fabricated on LED using the UV curing method. The HBr-H3PO4-K2Cr2O7 chemical etchant is developed for fabricating the circular 45 degrees corner reflector. The measured light-current curve of the proposed LED shows that, compared to conventional LEDs, the output power increases considerably at high current level and the linearity is significantly improved by the circular 45 degrees corner reflector. From the spectra measurement, we can confirm that the proposed LED structure shows combined characteristics of both conventional surface- and edge-emitting LEDs.