Tandem white organic light-emitting diodes adopting a C ₆₀ :rubrene charge generation layer

Abstract

Organic bulk heterojunction fullerence (C 60 ) doped 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) as the high quality charge generation layer (CGL) with high transparency and superior charge generating capability for tandem organic light emitting diodes (OLEDs) is developed. This CGL shows excellent optical transparency about 90%, which can reduce the optical interference effect formed in tandem OLEDs. There is a stable white light emission including 468 nm and 500 nm peaks from the blue emitting layer and 620 nm peak from the red emitting layer in tandem white OLEDs. A high efficiency of about 17.4 cd/A and CIE coordinates of (0.40, 0.35) at 100 cd/m 2 and (0.36, 0.34) at 1000 cd/m 2 have been demonstrated by employing the developed CGL, respectively.

Indanone‐Based Copper(II) Molecular Materials as Potential Semiconductors for Optoelectronic Devices

“…The requirements for the design and manufacture of active layers in OLEDs are the presence of π-conjugated semiconductors with high quantum yields, having a high thermal stability, and the ability of these semiconductors to form continuous and morphologically stable films or layers. [5][6][7][8][9][10] The films that integrate the OLEDs are of nanometric thickness, which allows them to be deposited on flexible substrates, and to find different applications to the conventional light emitting diodes (LEDs) such as, in display of telephones or flexible screens. The organic semiconductors forming the films, must be coated, printed, or evaporated on a flexible substrate such as polyethylene terephthalate (PET).…”

Tandem Organic Light‐Emitting Diodes

“…Most investigations on tandem OLEDs have been done related to the compositions of the intermediate connectors and mainly focus on their electronic properties . The intermediate connector can be formed using: i) inorganic/inorganic layers, ii) organic/inorganic layers, or iii) organic/organic layers …”

“…The typical n‐doped organic layer can be selected from Li‐, Rb‐, Cs‐, or Mg‐doped ETLs, such as Alq 3 (Bphen or BCP):Li, Bphen:Rb 2 CO 3 , Alq 3 (Bphen or BCP):Cs, Alq 3 (or BCP):Cs 2 CO 3 , Bphen:CsN 3 , and Alq 3 (or Bphen):Mg . The typical metal‐oxide layer can be selected from MoO 3 , WO 3 , V 2 O 5 , indium tin oxide (ITO), and ReO 3 . In addition, there are a few other intermediate connectors, such as PEGDE/Al/MoO 3 , LiF/Al/HAT‐CN, and LiF/ZnPc:C 60 /MoO 3 .…”

“…Typical intermediate connectors of this type are “n‐type doped ETL/MoO 3 (or WO 3 )” and “n‐type doped ETL/HAT‐CN” . It is worth mentioning that strong oxidizing agents, such as FeCl 3 , F 4 ‐TCNQ, WO 3 , MoO 3 , and HAT‐CN can be of p‐type dopants to create holes in the doped HTLs.…”

“…The transparency and the thickness of the connector affect the light output of the device. Therefore, many studies have been carried out on the construction of the intermediate connectors . However, a systematic understanding of the mechanism of the intermediate connectors and how to form ideal intermediate connectors in the devices is very much needed in order to facilitate further studies of high‐performance tandem OLEDs.…”