Organic electroluminescent device

• US 20040027059A1
• Filed: 07/28/2003
• Published: 02/12/2004
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Tsutsui, Tetsuo
• Granted Patent: US 7,291,969 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 71/841 Applying alternating current [AC] during manufacturing or treatment
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

An organic electroluminescence device of the present invention adapts a new concept in its configuration to improve its efficiency in addition to obtain a high reliability and good yielding. The organic electroluminescent device having an electroluminescent film containing an organic material capable of causing an electroluminescence and being arranged between a first electrode and a second electrode, includes: a carrier generation layer, which is a floating electrode, is embodied in the electroluminescent film; an insulting film between the first electrode and the electroluminescent film, and an insulating film between the second electrode and the electroluminescent film, wherein the organic electroluminescent device is driven by an alternating current bias.

Claims

1. An organic electroluminescent device comprising:

a first electrode;

a second electrode; and

an electroluminescent film containing an organic compound capable of causing an electroluminescence and being provided between the first electrode and the second electrode,

wherein a carrier generation layer is embodied in the electroluminescent film, said carrier generation layer being a floating electrode;

wherein a first insulting film is provided between the first electrode and the electroluminescent film, said first insulting film preventing a carrier injection from the first electrode to the electroluminescent film; and

wherein a second insulating film is provided between the second electrode and the electroluminescent film, said second insulating film preventing a carrier injection from the second electrode to the electroluminescent film.

2. An organic electroluminescent device as claimed in claim 1, wherein the organic electroluminescent device is driven by an alternating current bias.

3. An organic electroluminescent device as claimed in claim 1, wherein the electroluminescent film includes a layer having bipolar property.

4. An organic electroluminescent device as claimed in claim 1, wherein the electroluminescent film includes an organic compound having electron-transporting property and an organic compound having hole-transporting property in combination with each other to form a bipolar mixed layer.

5. An organic electroluminescent device as claimed in claim 1, wherein the electroluminescent film comprises a polymer having bipolar property including a π

-conjugated system or a σ

-conjugated system.

6. An organic electroluminescent device as described in claim 1, wherein the carrier generation layer contains an organic compound.

7. An organic electroluminescent device as described in claim 6, wherein the carrier generation layer contains at least one of an acceptor and a donor for the organic compound.

8. An organic electroluminescent device as described in claim 6, wherein the carrier generation layer contains both an acceptor and a donor for the organic compound.

9. An organic electroluminescent device as described in claim 1, wherein the carrier generation layer has an electric conductivity of 10⁻

10 S/m or more.