Creating White Light Using LEDs

When it comes to creating white light using LEDs, there are many different methods, all of which have their advantages and disadvantages. First, the most common and traditional is chip-level conversion, where the converting material is integrated directly onto a blue LED die or fills up the LED package volumetrically. A second method converts the blue light of a diode far away from the chip, which utilizes a mixing chamber and remote optic integrating a converting phosphor, fluorescent dye, quantum dots, or other converting material. Yet another method is color mixing using LEDs of different colors such as red, green, and blue, where each LED’s intensity is varied additively to create the desired color temperature. Each method presents different challenges and brings to the designer different advantages from a system performance perspective with regards to system efficacy, CRI, optical efficiency, energy efficiency, heat sinking and other design considerations. It is important for designers to understand the nuances of each method when deciding on which method to use, whether one is selecting the light engine to be used in design of a new fixture, or selecting the type of fixture to be used in a given application.