Determining phosphors' effective quantum efficiency for remote phosphor type LED modules

摘要

Remote phosphor type light-emitting diodes (LEDs) are gaining popularity in all kinds of solid-state lighting applications. Main reasons are the high luminousefficiency in comparison with proximate phosphor type LED devices and the improved spatial color uniformity due tointernal photon scattering. Optical properties of a high-power white LED are highly dependent on the powerand the temperature of the diode junction and phosphor. For a remote phosphor type LED module, junction and phosphortemperature can be very different. The effect of excitation light density, junction temperature, and ambient temperature on phosphor heating has therefore beenstudied. Results have been used to determine the effective quantum efficiency of remote phosphors as a function ofphosphor temperature and pump light density.