以全溶液及轉貼技術製作小分子白色有機發光二極體

Using Stamping Transfer and All-Solution Processes to Fabricate Small Molecular White Organic Light-Emitting Diodes

林揚靖(Yang-Ching Lin)

指導教授 ： 莊賦祥

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2014年)

摘要

本論文研究利用轉貼方式，製作電子傳輸層，防止有機層之間互溶情形，達到多層式有機發光二極體。首先利用PEDOT:PSS作為電洞注入層、發光層使用高能量轉移的磷光主體材料26DCzppy，並摻雜藍色和紅色磷光材料FIrpic、Hex-Ir(phq)3，以溶液製程方式進行旋轉塗佈成膜，接著製作PDMS膜，將電子傳輸層(Electron Transport Layer ETL)TPBi，塗佈在PDMS膜上，進行轉貼技術，以熱壓方式轉貼於發光層上，再蒸鍍陰極電極LiF/Al，即可得到以全溶液製作的小分子白色有機發光二極體。轉貼製程參數壓印時間，與PDMS膜經UV-OZONE表面改質時間都是關鍵之一，因此TPBi要成功轉貼於EML上必須調整製程最佳化參數，才能轉印於元件上。本研究最佳元件結構: ITO /spin- PEDOT: PSS(50nm)/spin-26DCzppy:FIrpic:Hex-Ir(phq)3(42nm)/stamping- TPBi(27-32nm)/LiF(0.6nm)/Al(150nm)。藍光元件在電流密度50mA/cm2下，亮度為1240 cd/m2且發光效率2.48cd/A。白光元件在電流密度10 mA/cm2下，亮度為892 cd/m2且發光效率8.9 cd/A，CIE(0.33,0.37)。且在嘗試加入電洞傳輸層後，使用交聯電洞傳輸材料(Cross-linkable HTM) TCTA，以半蒸鍍方式代替轉貼方式製作ETL，排除轉貼不穩定性，來驗證效果，來達到多層式OLED，比較多層元件結構為:ITO/spin-PEDOT: PSS(50nm)/spin-TCTA(35nm)/spin-26DCzppy:FIrpic:Hex-Ir(phq)3(42nm)/evap.- TPBi(30nm) /LiF(0.6nm)/Al (150nm)，在電流密度10mA/cm2下，亮度為972 cd/m2且發光效率可達9.73cd/A，驅動電壓可從原本沒加入電洞傳輸層材料之元件8.2V降為6.8V，由此發現加入TCTA，電洞傳輸特性較佳，提升電洞傳輸速率，加強載子複合區域，在高電壓下之亮度有顯注的提升，驅動電壓也大幅下降。與全溶液製作而成白光元件相比較之下，光電特性相差很小。

關鍵字

全溶液製程 ； 轉貼 ； 有機發光二極體 ； 小分子 ； 磷光

並列摘要

In this study, using stamping transfer process, fabricate an electron transport layer, to prevent the situation mutual solubility between organic layer; achieved multi-layer organic light-emitting diodes. First, using PEDOT: PSS as the hole injecting layer. The emitting layer using a high energy transfer phosphorescent host material 26DCzppy, and blue and red phosphorescent dopant material FIrpic、Hex-Ir (phq)3, All solution process coating by way of rotation formed, fabricated PDMS film, the ETL (Electron Transport Layer) TPBi, spin coated TPBi on PDMS film technology for posted to pressing on the light emitting layer transfer method, the vapor deposition of the cathode electrode LiF / Al. Then, get the all solution process of small molecule white organic light- emitting diodes. The transfer process keys included stamping time, with the PDMS film by UV-OZONE surface modification time is one of the key. The TPBi film transfer successfully on EML optimized parameters must be adjusted in order to transfer in device. This study device structure: ITO / spin-PEDOT:PSS (50nm) / spin-26DCzppy: FIrpic:Hex-Ir(phq)3 (42nm)/stamping-TPBi(27- 32nm)/LiF(0.6nm) /Al(150nm).Blue device the luminance of 1240 cd/m2, the current efficiency of 2.48 cd/A at 50mA/cm2 ,and white device the luminance of 892 cd/m2, the current efficiency of 8.9 cd/A, and CIE (0.33, 0.37) at 10mA/cm2.The study of added hole transport layer, using cross-linked hole transport material (Cross-linkable HTM) TCTA, using a half deposition instead of stamping methods to fabrication ETL, stamping exclude instability ,achieved a multi-layer OLED. Compared to multi-layer device structure: ITO/spin-PEDOT:PSS (50nm)/spin- TCTA(35nm)/spin- 26DCzppy:FIrpic:Hex-Ir(phq)3(42nm) /evap.-TPBi(30nm)/ LiF(0.6nm) /Al(150nm).The luminance of 972 cd/m2, the current efficiency of 9.73 cd/A at 10mA/cm2, driving voltage of device from 8.2 V degrade to 6.8 V when device add the hole transport layer. A result discovered that adding TCTA, hole transport characteristics better and enhance the hole transfer rate, strengthening the carrier recombination region. Significantly improved luminance at high voltage, the driving voltage has decreased significantly. Compared to all solution processes white device, the optical properties of difference is small.

並列關鍵字

All-solution process ； Stamping ； Organic light-emitting diodes ； Small molecules ； Phosphorescent

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