高濃度YAG螢光粉光學模型之建立與分析

Optical Modeling of YAG Phosphor in Higher Concentration for White LEDs

丁姿妍(Zi-yan Ting)

指導教授 ： 孫慶成 ； 楊宗勳

國立中央大學/理學院/照明與顯示科技研究所/碩士(2014年)

摘要

本論文中，使用噴塗形式封裝技術建立高濃度螢光粉光學模型。光學模型包含了散射模型、吸收係數與轉換效率等光學特性，光線於螢光粉膠體中的散射行為，我們將利用蒙地卡羅光追跡法結合米氏散射理論來描述，藉由藍光與黃光兩次光追跡來描述白光的光學特性，接著經由實驗與模擬來分析吸收係數與轉換效率。另外，由於螢光粉對不同波長激發光的吸收能力皆不相同，最後將引入β參數來提高螢光粉模型在色彩表現預測的準確性。最後比較實際封裝與模擬結果，分析在不同相關色溫下之頻譜與色座標、封裝效率及空間色彩分佈，藉此驗證此高濃度螢光粉光學模型之準確性。

關鍵字

螢光粉光學模型 ； 散射模型 ； 吸收係數 ； 轉換效率 ； β校正

並列摘要

In this thesis, we have successfully built up an optical modeling of YAG phosphor in higher concentration with conformal coating. The optical modeling process includes scattering modeling, absorption coefficient and conversion efficiency. We simulate the scattering properties in YAG phosphor with Mie scattering theory based on Monte Carlo ray tracing. The simulation includes the optical behaviors of blue lights and yellow lights. The experimental measurement results are applied to figure out the absorption coefficient and conversion efficiency. Since the absorption and the emission of the phosphor is a function of incident wavelength, we introduce a β factor to increase the accuracy of phosphor simulation. Finally, we analyze the spectrum, color coordinate, packaging efficiency, and angular correlated color temperature distribution of white LEDs at different correlated color temperatures for the experimental and simulative results to verify the precision.

並列關鍵字

optical modeling of phosphor ； scattering modeling ； absorption coefficient ； conversion efficiency ； β modification

參考文獻

[25] 紀葦世，高效能YAG螢光粉之特性量測與模型，元智大學光電工程研究所碩士論文，中華民國九十九年。

[3] Restriction of Hazardous Substances Directive, http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive.

[8] N. H. Jr. and S. F. Bevaqua, “Coherent (visible) light emission from Ga(As1–xPx) junctions,” Appl. Phys. Lett. 1, 82-83 (1962).

[12] S. Nakamura, T. Mukai, and M. Senoh, “Candela-class high-brightness InGaN/AlGaN double-heterostructure blue-light-emitting diodes,” Appl. Phys. Lett. 64, 1687-1689 (1994).

[14] Y. Narukawa, M. Ichikawa, D. Sanga, M. Sano, and Takashi Mukai, “White light emitting diodes with super-high luminous efficacy,” J. Phys. D: Appl. Phys. 43 354002 (2010).