利用溶液製程與轉貼技術探討電洞注入層和發光層最佳化結構之有機發光二極體

本研究是利用溶液製程和轉貼技術製作小分子有機發光二極體，其結構為ITO/PEDOT: PSS/26DCzPPy: FIrpic/TPBi/LiF/Al。而電洞注入層材料為PETDOT:PSS利用旋轉塗佈的方式旋塗於ITO上，藍色發光層為26DCzPPy摻雜FIrpic並加入於氯苯溶劑中，其26DCzPPy材料特性高三重態能階能有效拘限激子於發光層內。本研究另一重點為利用轉貼技術達到全溶液製程方式製作有機發光二極體，先將電子傳輸層材料TPBi旋塗於PDMS基板上，再利用轉貼方式壓印在發光層上。TPBi材料特性有阻擋電洞電流，能有效達到高能量轉換，陰極則為LiF/Al於真空蒸鍍製作。而TPBi轉貼方式是將旋塗於PDMS基板上的膜壓印於發光層，其加壓重量為0.5 kg/cm2同時加熱120 0C時間為100秒。藍色元件在最佳條件下效率達3.5 cd/A，色座標為(0.16, 0.30)在電流密度為20 mA/cm2。另一研究是利用實驗設計的曲面反應法來預測其藍色元件最佳化的參數，由上面所提到的轉貼技術，由於在實驗設計法的狀態下TPBi轉貼技術為不能控制因子，所以將TPBi利用熱蒸鍍的方式製作降低其不穩定的情形，厚度固定為30 nm。將PEDOT:PSS與26DCzPPy:FIrpic的轉速定義為重要的輸入因子而輸出因子定義電壓與電流效率，由程式Design Expert Software verifying V8.0.6.設計出13組初始參數。其最佳化參數利用變異數分析法預測最佳化，在利用實驗驗證。其元件最佳結果在電流密度為20 mA/cm2下，效率達8.75 cd/A，操作電壓為6.1 V。

關鍵字

溶液製程；轉貼技術；有機發光二極體；實驗計畫法；反應曲面法

並列摘要

In this thesis, a blue small- molecular organic light- emitting diodes (SM- OLEDs) based on a solution-process and stamping transfer method were first investigated. The structure of OLEDs device is described as follows: ITO/PEDOT: PSS/26DCzPPy: FIrpic/TPBi/LiF/Al. Therein, PEDOT: PSS as a hole injection layer is formed onto ITO-glass via spin-coating; emitting layer consists of host material 26DCzPPy with high triplet energy and blue dopant FIrpic are mixed and dissolved in chlorobenzene to form onto PEDOT: PSS layer by spin-coating. A specialized fabrication process-stamping method is utilized to transfer the TPBi film that plays an important role as electron transporting layer and also a hole blocking layer, from PDMS surface onto the 26DCzPPy: FIrpic. LiF/Al is thermally evaporated as a cathode electrode. The external pressure applied during for stamping TPBi was kept at 0.5 kg/cm2 and the heating temperature was carried out at 1200C for 100 seconds. A blue small- molecular organic light emitting diodes with CIE (0.16, 0.30) and the highest 3.5 cd/A of current efficiency at current density 20 mA/cm2 was obtained with entire solution-based process with stamping. Design of experiment (DOE) with response surface methodology (RSM) was applied to optimize the current efficiency of OLED devices. In this case, TPBi was fabricated via vacuum-deposition with thickness of 30 nm. The thickness of the hole injection layer (PEDOT: PSS) and the emitting layer (26DCzPPy: FIrpic) are chosen as two main input factors of processes. 13 OLED devices with different parameters were conducted following by an initial setting of Design Expert Software version V8.0.6. The optimum process parameters are forecasted by verifying the factors of output quality characteristics via analysis of variance (ANOVA). Finally, an impressive result 8.75 cd/A of current efficiency at 20 mA/ cm2, and a low 6.1 volt of driving voltage at 100 cd/m2 of luminance was reached by DOE with RSM.

並列關鍵字

solution-process ； stamping-method ； OLEDs ； design of experiments ； response surface methodology

參考文獻

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利用溶液製程與轉貼技術探討電洞注入層和發光層最佳化結構之有機發光二極體

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