改善濕式刮刀製程高效率小分子OLED之互溶問題

Abstract

利用刮刀塗佈高效率小分子OLED會造成層與層之間的互溶情形，此論文將討論如何觀察此互溶情形及利用製程的改進與蒸鍍製程之元件做相互比較。將第一層電洞傳輸層材料N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine ( NPB ) 以反應式離子蝕刻機 ( RIE ) 蝕刻出明確之邊界，最後塗佈發光層並改變電洞傳輸層之厚度、加熱條件、吹風條件以及溶劑選擇，最後以螢光顯微鏡觀察其邊界之變化，發現當HTL厚度越薄其邊界之退後情形較為明顯，邊界退後程度依序為：15 nm＞20 nm＞30 nm＞35 nm，而在成膜時有外加吹風加熱條件之退後情形明顯優於無吹風加熱之條件，邊界退後程度依序為：無吹風無加熱＞有吹風有加熱，溶劑的選擇上，其邊界退後程度依序為：氯苯 ( Chlorobezene )＞三氯甲烷 ( Chloroform )＞甲醇 ( Methanol )＞甲苯 ( Toluene )，其中甲醇不含溶質；再以溶解性挑選較難溶解 NPB的 CB作為 EML之溶劑，結構如下： ITO / PEDOT / NPB / PO-01-TB：CBP / TPBi / LiF / Al，效率在 EML為 20 nm達：20.5 lm/W、33.82 cd/A，EML為30 nm達：19.74 lm/W、41.32 cd/A。

The blade coating cause the high efficiency small molecule OLED dissolving the interface between organic layers, this thesis discuss how to observe this situation and the use blade coating process improvement and evaporation process of the component to compare to each other. The first layer ( HTL ) of material is N, N'-bis (naphthalen-1-yl)-N, N'-bis (phenyl)-benzidine ( NPB ), then etching clean boundary by reactive ion etching, and depositing emitting layer by blade coating. Changing the thickness of the HTL, heating conditions, blower conditions, and selection of solvent, and finally to fluorescence microscopy observed changes in boundary conditions and found that when the thickness of the thinner HTL back the boundaries of its more obvious case, the boundary back order of degree: 15 nm> 20 nm> 30 nm> 35 nm, when there is external blower and heating conditions of the situation is better than no blower and no heating conditions, boundary degree back in order: no blower and no heating> blower and heating, the choice of solvent, the boundary back order of degree: chlorobenzene > chloroform > methanol > toluene, methanol without solute ; Select CB as the solvent of EML, the following structure: ITO / PEDOT / NPB / PO-01-TB: CBP / TPBi / LiF / Al, the efficiency of the EML to 20 nm: 20.5 lm / W, 33.82 cd / A, EML to 30 nm up to: 19.74 lm / W, 41.32 cd / A.