Examine the mutual dissolution to develop small-molecule organic light-emitting diodes by blade coating

• Main Author: 劉益倫
• Other Authors: 洪勝富
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/58150257305745515667

碩士 === 國立清華大學 === 光電工程研究所 === 101 === In this thesis, our team try to develop a blade technique for the making of multilayer organic light-emitting diodes (OLEDs). During the solution process, it has been found that material fail to be coated perfectly due to the mutual dissolution problem. Compared to other processing solution such as small-molecular OLEDs reports, an additional hole blocking / electron-transport layer, which was made by thermal vapor deposition, our hole-blocking / electron-transport layer was made via blade coating method. To solve the mutual dissolution problem, we used the reactive ion etching (RIE) to create a clear boundary, then coating the 2nd organic thin with different solvents. Finally, the phenomenon on the boundary by fluorescence microscopy was observed. The roughness and the thickness of each layer to decrease the inter-miscible were also examined. It was found that when the blade speed was faster, the influence of mutual dissolution was lesser, especially when the good volatility solvent was used. For the Blue multilayer organic light-emitting diodes, the electron-blocking layer material (EBL), bis[4-(p,p′-ditolyl-amino)phenyl]diphenylsilane (DTASi), with high triplet excited state of 2.95 eV, high-lying LUMO level of 2.25 eV was not useful, as a common phenomenon Redshift was observed.