LED aging acceleration — An analysis from measuring and aging data of 14,000 hours LED degradation

In the LM 80 testing standard method the lumen maintenance [1] of light sources is measured during their lifetime. As long as the spectral behavior is not changing over time, there is no doubt in that method. Since the integral value of the luminous flux is weighted with the V(λ)-function, degradation in the red and blue parts of the spectrum are represented less than changes in green and yellow spectral ranges. For this purpose spectral bands and their ratio over lifetime are analyzed and compared to each other. Data of 14,000 hours are presented in this study. Aging curves of the luminous flux und optical power are compared and analyzed by the described methods. Extrapolation and accelerated lifetime tests are used to predict spectral changes and their characteristics.