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. 18, 2015
Filed:
Mar. 05, 2007
Nobuharu Ohsawa, Zama, JP;
Satoshi Seo, Kawasaki, JP;
Hiroko Murata, Odawara, JP;
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Abstract
It is an object to provide an element structure which is suitable for a light-emitting element using a phosphorescent compound. It is another object to provide a light-emitting element with high luminous efficiency by using the element structure. In particular, it is another object to provide a light-emitting element with high luminous efficiency and long life. A light-emitting element is manufactured, which includes a first light-emitting layer and a second light-emitting layer provided to be in contact with each other between a first electrode and a second electrode, where the first light-emitting layer includes a hole transporting host material and a phosphorescent compound, and the second light-emitting layer includes an electron transporting host material and the phosphorescent compound.