| dc.description.abstract | n this thesis, real package experiments are used to find out the distribution of the ratio of the green and red phosphors and the color rendering index in the Chromaticity Coordinates. With the ratio of green and red phosphors, the optical phosphor model can be established with mixture of double layers. Light scattering can be simulated with Mie scattering based on Monte Carlo ray tracing in phosphor layer. Also, with experiments, these parameters can be captured including blue power, green power and red power in the white light. Besides, absorption coefficient and conversion coefficient are employed to simulate the power of blue, green and red lights in white LED.
Since the absorption and emission of the phosphor is a function of incident wavelength, we introduce a β factor to increase the accuracy of phosphor simulation. Despite blue light spectrum, by the analysis of emission spectrum and absorption spectrum of red and green phosphors, we investigate the effect of re-absorption in the package of double phosphors in order to improve the distortion of green emission spectrum. Finally, with the verification of experiment and the analysis of simulation, we successfully establish the two phosphors model with double layers, which can be used to predict the manifestation of color in white LED with different forms of packaging.
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