目前LEDs發光效率不佳，只有傳統照明設備的一半，近年來隨著奈米科技的蓬勃發展，將LEDs發光層以超晶格薄膜取代可有效提升發光效率，不過以往利用分子束磊晶法製造的超晶格薄膜卻有生產成本高昂與製造過程需不斷更換鈀材的缺點，而自組裝技術產生超晶格薄膜結構就顯得容易許多且成本低廉，此法是透過調控奈米微粒間不同作用勢能之強弱來獲得超晶格薄膜結構，若能有效掌握超晶格薄膜的缺陷特性則可望改善發光效率約25%，但是以往傳統模型對於預估獲得具有優良結晶性超晶格薄膜之製程參數仍力有未逮，因此，本研究將建構一套完整之超晶格薄膜成形理論與發光效率估算模型及其電腦模擬系統，以針對超晶格薄膜對提升發光效率相關課題進行研究探討。
首先，本研究以微觀的角度探討奈米微粒在液體中所受到的作用勢能，接著利用布朗動力之Langevin方程建構自組裝超晶格薄膜結構模擬系統，配合缺陷係數( )分析超晶格薄膜結構之聚集缺陷特性，並使用實驗設計方法進行模擬實驗，找出顯著參數因子及建構顯著參數因子之理論模型。同時利用發光效率估算模型，將奈米微粒視為點光源並計算超晶格薄膜內光波的耦合疊加效應，進而推估發光效率，並將本文模擬結果與文獻資料比對，證實本研究所建構之理論模型的正確性與可行性。隨即將模型電腦化，以系統化的方法執行顯著參數因子之調控模擬與估算發光效率，接著根據本文所建構之設計流程應用於提升發光二極體之發光效率，以驗證本研究之實用性。
由本研究所建構之超晶格薄膜成形理論模型，在模擬過程中除了考量以往傳統模型之漢馬克係數與表面電荷之外，並加入粒子濃度與偶極矩的影響，且經由實驗設計方法建立顯著參數因子及其交互作用之理論模型。除了發現上述參數對超晶格薄膜缺陷特性具有顯著影響之外，參數彼此間之交互作用對超晶格薄膜缺陷特性亦具有顯著影響。在與文獻資料比對後，發現本文理論模型在同質系統時可有效將發光效率平均估算誤差由27.54%降低至7.42%，異質系統亦可將誤差由34.16%降到5.36%，顯示本文理論可精確預估超晶格薄膜之發光效率。透過發光二極體內發光層之超晶格薄膜結構的設計規劃應用實例，使發光效率由12.33%提高到21.4%，證實本文可快速精確的找出最佳發光效率之超晶格薄膜結構與製程參數設定範圍。

In the past, the luminescence efficiency of light emitted devices (LEDs) doesn’t work as expected. By using superlattices can be enhanced the luminescence efficiency of LEDs. The principle thing while producing the superlattices film of active layer of LEDs was molecular beam epitaxy. The disadvantages include high manufacturing cost and targets have to be kept modifying. Furthermore, by using self-assembly technology to produce superlattices thin film it can lower the production costs effectively. This is the way through controlling the potential energy between particles to obtain the superlattices thin film. However, by controlling the defect property of superlattice thin film it can be expected to improve around 25%. This study intends to construct an intact theory and computer simulation method in an attempt to probe into the subject of enhancing the luminescence efficiency based on the development of a self-assembly nanoparticles superlattices film formation theory and a luminescence efficiency estimative model.

First, this research uses microcosmic way to confer the potential while nanoparticles are under the fluid. Then, we use the Langevin equation from Brownian dynamics approach to construct the simulation system to analyze crystal aggregation characteristics of superlattices film via defect factor reduction. Moreover, the simulations were executed through experimental design method. Then, the theoretical model was developed by significant factors. At the same time, by using the luminescence efficiency estimation model, the luminescence efficiency was estimated via calculating the light coupling effect on the superlattice thin film. The results obtained by using the present model were found agree well with experimental data in literature. After that, we can computerize the model using the systematized approach to execute the simulation and to estimate the luminescence efficiency. Finally, we can apply the design procedure which was designed meet the research goal of active layer properties of LEDs to prove the practicability of this research.

The model parameters include the surface charge, Hamaker number, dipole moment and particle concentration. It is found via an experimental design method that system parameters and their interaction are significantly affecting the defect property of superlattice thin film. The average estimation error of the luminescence efficiency is decreased from 27.54% to 7.42% in the same material system, and the average estimation error of the luminescence efficiency is decreased from 34.16% to 5.36% in different systems. Also, through the proposed model of superlattices film luminescence efficiency, plan for improving luminescence efficiency can be obtained as soon as possible under the condition of several different limitary combination of parameters. Through practical examples of the superlattices film, active layer on the electroluminescence devices show that the proposed approach can find the best range of composition and parameter accurately for enhancing luminescence efficiency. It improves the luminescence efficiency from 12.33% to 21.4% at the range setting of system parameters.

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