English  |  正體中文  |  简体中文  |  Items with full text/Total items : 28608/40649
Visitors : 6425655      Online Users : 48
RC Version 4.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search

Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/51351

Title: Highly Twisted Carbazole–Oxadiazole Hybrids as Universal Bipolar Hosts for High Efficiency PhOLEDs
Authors: Shuo-Hsien Cheng
Wen-Yi Hung
Ming-Hung Cheng
Hsiao-Fan Chen
Gene-Hsiang Lee
Chin-Lung Chung
Tzu-Chin Yeh
Wei-Chieh Tang
Shou-Ling Huang
Ken-Tsung Wong
Contributors: 國立臺灣海洋大學:光電與材料科技學士學位學程(學系)
Date: 2015-11
Issue Date: 2018-11-23T06:17:01Z
Abstract: Abstract: Four bipolar molecules oDOXA, mDOXA, oOXA, and mOXA composed of a hole‐transport carbazole (donor, D) and an electron‐transport 1,3,4‐oxadiazole (acceptor, A) bridged with different π‐spacers (biphenyl or o‐terphenyl) are synthesized, characterized, and used as host materials for various colored phosphorescent OLEDs (PhOLEDs). The highly twisted geometry established via multiple ortho/meta‐connections effectively inhibits direct electronic D–A coupling and gives these bipolar molecules similar high triplet energies (≈2.70 eV). In addition, distinctive bipolar transport capabilities are observed by time‐of‐flight technique (μh ≈ μe ≈ 10−5–10−6 cm2 V−1 s−1). The D/A connection topology is found to subtly govern the physical properties, rendering these new molecules suitable for serving as bipolar host materials. Among the four host materials, oOXA using the tandem ortho‐linkage terphenyl as a linker outperforms the other three hosts in terms of the device efficiency, in which the maximum external quantum efficiencies (ηext) of the corresponding PhOLEDs are as high as 19.4%, 21.3%, 20.9%, 20.1%, and 19.0% for blue, green, yellow, orange, and red PhOLEDs, respectively. Moreover, a single‐host multilayered warm‐white OLED based on oOXA also shows remarkable efficiency (19.8%, 42.4 cd A−1, and 38.6 lm W−1) with high color‐rendering index of 86.8 and stable chromaticity.
URI: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/51351
Appears in Collections:[光電科學研究所] 期刊論文

Files in This Item:

File Description SizeFormat

All items in NTOUR are protected by copyright, with all rights reserved.


著作權政策宣告: 本網站之內容為國立臺灣海洋大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,請合理使用本網站之內容,以尊重著作權人之權益。
網站維護: 海大圖資處 圖書系統組
DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback