Process to measure particulate down-converting phosphors and create well-correlated software models of LED performance

White light-emitting diodes that use down-converting phosphors have been utilized in the illumination industry for several years. In many cases, little information needs to be known about the physics and performance of the phosphor itself to design, optimize, and simulate the light emission of the LED for the purpose of creating secondary optics. However, the importance of accurately accounting for the effect of the phosphor cannot be overstated when designing the LED package or when performing a tolerance analysis, for instance. The difficulties in gathering or measuring the relevant performance metrics of the phosphors are significant barriers to achieving accurate predictions in illumination software packages. This paper describes a simple, repeatable process to measure several phosphor performance metrics that are used, in turn, to create a model of the same phosphor in a commercially-available illumination software package. The measured values are used either as direct inputs or are used to derive the proper inputs for the software. Derivations and discussion about the software model are included. The performance of the simulated phosphor will then be compared and correlated to the physical measurements. Finally, a model of an LED that uses this phosphor model is built in software and its simulated performance is compared to measured values.