Comparative study on optical performances of ultraviolet light-emitting diodes using all-inorganic and organic silicone packaging structure

Abstract

Ultraviolet light-emitting diode (UVLED) has important application prospects in disinfection, sterilization, UV curing, full-spectrum lighting, etc. However, the low light extraction efficiency has severely limited the development of UVLEDs. At present, the two mainstream packaging technology routes for UVLEDs are using all-inorganic packaging structure and organic silicone packaging structure. Yet, there is no detailed study comparing the impact of these two structures on the optical performances of UVLEDs. Herein, this study compares these two kinds of UVLED packaging structures through optical simulation, referred to all-inorganic UVLED and organic UVLED. Simulation indicates that the surface reflectance and inclination angle of the LED bracket have a great impact on the optical performance. In the organic UVLED, the light extraction efficiency can be further improved by increasing the refractive index of organic silicone. After optimization, the radiant flux of organic UVLED is 3.3 times of the all-inorganic UVLED device, and the light output efficiency is improved by 32.6%. Therefore, from the perspective of optical energy utilization, the organic silicone packaging structure is more suitable for UVLED packaging. This research provides a design guide for improving the light output of UVLED devices.