本論文中，利用紅綠混粉半球封裝實驗，找出紅粉與綠粉比例與演色性在色度座標上的分佈，針對此紅粉與綠粉比例建立雙粉分層之螢光粉光學模型。我們利用米氏散射與蒙地卡羅光追跡法描述光在螢光膠體中傳遞的行為，接著配合實驗引入吸收係數與轉換係數來模擬白光LED中的藍、綠及紅光能量比。其中，由於螢光粉對不同波長激發光的吸收能力皆不相同，故引入β參數校正藍光頻譜經螢光膠體的形變。此外，除藍光頻譜外，藉由紅粉與綠粉之輻射頻譜與吸收頻譜的分析，探討雙粉封裝中再吸收的效應，改善綠光頻譜因再吸收效應而造成的形變。最後，經由實驗與模擬的驗證與分析，成功的建立出雙粉分層之螢光粉模型。此模型可用來預測不同封裝形式之白光LED的色彩表現。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.
