Fabrication of Lens With Large View Angle Through Droplet Evaporation for High-Power Light-Emitting Diodes

A simple and low-cost method for fabricating lens with large view angle was proposed based on droplet evaporation for high-power light-emitting diodes (LEDs). In such a method, an immiscible and vaporizable droplet was deposited on the top surface of a liquid silicone lens. By applying a heat load, the silicone was cured and the droplet was evaporated simultaneously. Then, lenses with craters were fabricated for large view-angle emission of LEDs. In experiments, the diameter and depth of the crater on the lens surface were controlled by adjusting the volume of droplet. As a result of the variation of carter size, light intensity distributions (LIDs) of LED modules were obviously modulated. Compared with traditional spherical cap lens, the view angles of the maximum light intensity of the fabricated lens varied from 0° to ±54°. Meanwhile, the maximum light intensity increased by 17%.