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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/59169


    Title: 白光LED之螢光粉多功能模型之研究;Study of multi-function phosphor modeling for white LEDs
    Authors: 陳靜儀;Chen,Ching-Yi
    Contributors: 光電科學與工程學系
    Keywords: 封裝效率;演色性;熱效應;白光LED封裝;螢光粉模型;CRI;package efficiecy;phosphor modeling;thermal effect;white LED packages
    Date: 2013-01-25
    Issue Date: 2013-03-25 15:55:27 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 在本論文中,著重於白光LED封裝螢光粉模型之建立,分別提出了螢光粉之演色性表現計算模型、等效光學模型與熱效應模型三種流程,可應用於白光LED封裝前的材料篩選,並可分析各種封裝體的效率與色彩表現,更可有效分析封裝體受熱後之色彩變化。首先利用頻譜線性疊加的方式,來完成預測演色性表現的計算模型。該模型是藉由調整白光封裝體之藍光晶片與雙色螢光粉的不同輻射頻譜比例,來計算其演色性表現在色座標上的分佈趨勢,最後利用不同的螢光粉參數進行封裝與量測來加以驗證。經由此計算模型的建立流程,可快速套用於任何雙色螢光粉體搭配藍光晶片的組合,進而分析其不同螢光粉配方於各種混光色溫之演色性表現。接著利用米氏散射原理結合蒙地卡羅光追跡法,描述光在螢光膠體中傳遞的行為來建立螢光粉等效光學模型,其中利用實驗量測搭配模擬來找出螢光粉光學模型之等效吸收係數與轉換係數。然而,由於螢光粉對不同波長激發光的吸收能力皆不相同,故本論文分別利用綠色螢光粉吸收頻譜搭配螢光粉吸收率,來校正藍光頻譜經過螢光膠體後的形變;並利用紅色與綠色螢光粉之吸收頻譜與輻射頻譜,分析再吸收效應對綠光頻譜造成的形變。並經由實驗與模擬的驗證,成功的建立出雙粉分層之螢光粉模型。藉由此雙色分層螢光粉等效光學模型的建立流程,可應用於各種雙色螢光粉體,來預測不同封裝型式之白光LED的光學與色彩表現,可有效分析各種封裝體的封裝效率。最後,利用實驗量測螢光粉薄片熱衰程度,並結合螢光粉光學模型,藉由此模型建立流程可用來預測與分析各種不同螢光粉配方與不同封裝型式之白光LED封裝體於不同操作溫度下,其色座標的變化趨勢。In this thesis, we studies the precise phosphor modeling of the white LEDs. We have developed the CRI calculation modeling, optical modeling, and thermal modeling of the phosphor. It can be applied for the material selection before the white light LED packaging and analysis of efficiency and color performance of white LEDs. The color variation due to the heating can be further analyzed.Firstly, the prediction calculation of CRI performance have been performed by a linearly calculation model. The mapping of CRI distribution on the color coordinate has been calculated by the adjusting of spectra ratio of blue chip and two color phosphor. The calculation results have been verified by the experiments of real package. The developed calculation modeling is simple and useful for predicting chromatic behaviors of a white LED with two phosphors.In the optical modeling, the scattering light can be simulated with Mie scattering based on Monte Carlo ray tracing in phosphor layer. Then use the experiment result and combine the simulation to fitting the effective absorption and conversion coefficients. Since the ability of absorption of the phosphor depend on the wavelength of excitation light, we combine the absorption spectrum of the green phosphor with the ratio of the phosphor absorption to modify the output spectrum of blue light. And we use the absorption spectrum of the red phosphor and the emission spectrum of the green phosphor to analysis the re-absorption effect. Finally, with the verification of real packages and the simulations, we successfully demonstrate the two phosphors model with double layers. The development of phosphor optical modeling can be applied to any recipe of phosphors for the prediction of chromatic performance and the analysis of package efficiency of white LED with difference package.In the thermal modeling, we combine the thermal effect of the phosphor with the optical model to build up the thermal model of phosphor. The thermal model can simulate color coordinate with various temperature. Finally, we can predict the variation of color behavior with different operation temperature in the white LED package.
    Appears in Collections:[光電科學研究所] 博碩士論文

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