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:
Aug. 05, 2014
Filed:
Feb. 18, 2010
Tohru Asari, Kitakyushu, JP;
Hiroyuki Hayashida, Kitakyushu, JP;
Kazuto Shiraishi, Kitakyushu, JP;
Takayuki Shimizu, Kitakyushu, JP;
Yasushi Koishikawa, Kitakyushu, JP;
Kazuaki Yoshimura, Kitakyushu, JP;
Tohru Asari, Kitakyushu, JP;
Hiroyuki Hayashida, Kitakyushu, JP;
Kazuto Shiraishi, Kitakyushu, JP;
Takayuki Shimizu, Kitakyushu, JP;
Yasushi Koishikawa, Kitakyushu, JP;
Kazuaki Yoshimura, Kitakyushu, JP;
Nippon Steel & Sumikin Chemical Co., Ltd., Tokyo, JP;
Abstract
Disclosed is a highly reliable organic electroluminescent device, in particular, a phosphorescent organic electroluminescent device using a low-molecular-weight host material, wherein a good balance between electron and hole injection and an efficient mechanism of phosphorescence are maintained. The organic electroluminescent device contains a light-emitting layer between an anode layer and a cathode layer and the light-emitting layer comprises a phosphorescent dopant material and a host material with a molecular weight of not more than 10,000. The host material is composed of a first host material and a second host material that is different from the first host material and the first host material differs from the second host material by not more than 0.1 eV in the ionization potential (IP), by not more than 0.1 eV in the electron affinity (EA), and by not more than 0.1 eV in the triplet energy (T1).