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:
Oct. 14, 2014
Filed:
Oct. 12, 2010
Ken Okamoto, Osaka, JP;
Ken Okamoto, Osaka, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An organic EL element () includes a light emitting layer () which has a two-layer structure, and a first light-emitting layer () is made from a host material which includes LUMO shallower than (i) LUMO () of a phosphorescent light emitting material and (ii) LUMO of a host material, from which a second light-emitting layer () is made. Further, the second light-emitting layer () is made from a host material which includes HOMO deeper than (i) HOMO () of the phosphorescent light emitting material and (ii) HOMO of the host material, from which the first light-emitting layer () is made. This makes it possible (i) to block holes from moving to the second light-emitting layer () and (ii) to block electrons from moving to the first light-emitting layer (). As a result, a probability that the holes and the respective electrons recombine with each other is increased. It is therefore possible to reduce a driving voltage of an organic EL element (). This improves light emitting efficiency.