Enhancing the optical properties of organic fluorine compound-encapsulated AlGaN-based ultraviolet light-emitting diodes with Ni/Au reflective electrodes

The development of AlGaN-based high-efficiency UVC-LEDs capable of effectively eliminating viruses and bacteria is desired. In this study, we demonstrate a significant improvement in optical output power (LOP) by applying optical interference technology and organic fluorine compound packaging technology. Experiments and calculations revealed that an improvement in LED die LOP was achieved through adjusting the optical length to approximately 0.7 center dot lambda n, resulting in an amplification of light intensity caused by the interference of light emitted perpendicular to the die. Furthermore, by coating the LED die with an organic fluorine compound and packaging it in a quartz lens, the LOP increased by a factor of 1.5. Ray-tracing analysis showed that, due to optical interference, the LOP of the LED die was more dependent on the light output from the top surface than from the side.