Electrothermal characterization applied to the study of chromaticity coordinates in RGB LEDs

The purpose of this paper is the development of a methodology to analyze the chromaticity coordinates in RGB LEDs, considering the influence of junction temperature. A review of theoretical concepts of colorimetry was performed, as well as a demonstration of the luminous flux equation that considers the effect of thermal and electrical characteristics of LEDs. The equations which represent the heatsink and junction temperature of the LEDs are compared with finite element simulations and experimental measurements. The equation of the luminous flux is related to the matrices of the tristimulus, to achieve a precise relationship between the LED´s operation condition and the desired color. Finally, tests in order to verify the data mathematically obtained in comparison with the data experimentally obtained are performed and shown.