The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 05, 2007
Filed:
Sep. 03, 2004
Yong Qiu, Beijing, CN;
Juan Qiao, Beijing, CN;
Jianhua Wang, Beijing, CN;
Liduo Wang, Beijing, CN;
Lian Duan, Beijing, CN;
Gangtie Lei, Beijing, CN;
Yong Qiu, Beijing, CN;
Juan Qiao, Beijing, CN;
Jianhua Wang, Beijing, CN;
Liduo Wang, Beijing, CN;
Lian Duan, Beijing, CN;
Gangtie Lei, Beijing, CN;
Tsinghua University, Beijing, CH;
Beijing Visionox Technology Co., Ltd., Beijing, CH;
Abstract
The present invention relates to a series of carbazole derivatives which are used in organic electroluminescent devices as the phosphorescent host materials of the emissive layers. The carbazole derivatives have glass transition temperature of between 70° C. and 220° C. and triplet energy of 2.62 eV or more. The carbazole derivatives comprise two carbazole groups and alkyl group and/or spiro group inserted between the carbazole group and aromatic group, which is represented by formula 1. The carbazole derivatives according to the present invention are used as host materials for the triplet emissive dyes and they have high energy and stability. They can also reduce the converse energy transfer from the dye molecules to the host molecules and improve the luminance and efficiency of the OLEDs, especially the efficiency and lifetime of the blue triplet OLEDs.