應用田口法於藍色螢光有機發光二極體製程參數
最佳化之研究

本研究一開始係使用具高Tg之電洞傳輸材料(HTG-1、HTG-2)來取代一般電洞傳輸材料(NPB)，製備基本綠色螢光有機發光二極體，利用材料具有高Tg之特性來提升元件熱穩定性，以防止元件發光時內部所累積之焦耳熱使材料結晶化進而影響元件發光效率，經實驗證明當使用高Tg材料HTG-1時其元件有較好之發光特性。接著將此高Tg之電洞傳輸材料導入藍色螢光結構中，並應用田口法與實驗計劃法進行實驗的規劃與配置來製備藍色螢光有機發光二極體，在製程中以有效且快速的方式來調變元件結構參數，將元件驅動電壓、發光亮度、發光效率及元件色座標值設定為輸出目標函數，利用統計檢定的方法藉由反應曲面法將實驗結果進行變異數分析分析，檢定對輸出目標函數之影響因子，並由迴歸分析推演出方程式，來預測元件結構最佳參數組合，有效的達到所設定之最佳元件發光特性。經由分析後所建議之最佳參數組合進行實際驗證，其元件於電流密度50 mA/cm2下其驅動電壓為8.28 V，發光亮度為4701 cd/m2，發光效率為9.48 cd/A。另外亦改變電子傳輸材料及微調有機層厚度來提升電子注入的效果，並藉由控制元件中載子再結合區於發光層中間以擴大發光區域，進而大幅提升元件發光效率。結果顯示，元件在電流密度50 mA/cm2下，驅動電壓為8.99 V，發光亮度為5634 cd/m2，發光效率為11.52 cd/A。

關鍵字

田口法；變異數分析；反應曲面法；最佳化；螢光有機發光二極體

並列摘要

In this study, we used hole transport materials (HTG-1 and HTG-2) with high glass transition temperature (Tg) to replace NPB of green OLED devices, experimental results high Tg of hole transport material HTG-1 can reduced to operate the OLED elements in a long time, the heat generated by components within the organic material to crystallized effect and increase luminance efficiency. By using, the high Tg of hole transport material applied in structure, and using Taguchi’s parametric design method OLED device with blue emitting-light can be fabricated, then relevant theory of statistical techniques was employed to discuss the influence of individual process parameters. Optimum process parameters were be forecast by verifying the factors of output quality characteristics by Analysis of Variance (ANOVA) and deducing response surface equation by Regression Analysis. Finally, by optimizing device structure, the driving voltage was 8.28 V, luminance of 4701 cd/m2 and luminance efficiency of 9.48 cd/A at the current density of 50 mA/cm2 can be achieved. In addition, we also change electron transport materials and adjustment organic layer thickness to improve charge carrier injection and confine triplet excitons in emitting layer, and then controlle the excitons generation zone in the middle of the emitting material layer and extended the recombination zone were achieved. Experimental results demonstrated that the blue OLED with current density of 50 mA/cm2, the driving voltage was 8.99 V, luminance of 4701 cd/m2 and luminance efficiency reached 9.48 cd/A can be fabricated.

並列關鍵字

Taguchi Method ； Analysis of Variance (ANOVA) ； Response Surface Methodology (RSM) ； Optimization ； Fluorescent OLED

參考文獻

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