Degradation Mechanisms and Reactions in Organic Light-Emitting Devices.

Novel tricarbazole compounds are provided. By appropriately selecting the nature of the tricarbazole substituents, compounds with appropriate HOMO and LUMO energies can be obtained for use as materials in a secondary hole transport layer.

Organic Electroluminescent Materials and Devices

An organic light emitting device is provided. The device has an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer further comprising an emissive material having the structure: (I) M may be a metal having an atomic weight greater than 40. R3 may be a substituent having a Hammett value less than about -0.17, between about -0.15 and 0.05, or greater than about 0.07. R5 may be H or any substituent. A may be a 5 or 6 member heteroaryl ring system. 'm' may be at least 1. 'n' may be at least zero. (X-Y) may be an ancillary ligand. The emissive material itself is also provided. The emissive material may have improved stability, and may provide a saturated blue emission.

Organic light-emitting materials and devices

Compounds comprising phosphorescent metal complexes comprising cyclometallated imidazo[1,2-f]phenanthridine and diimidazo[1,2-a:1′,2′-c]quinazoline ligands, or isoelectronic or benzannulated analogs thereof, are described. Organic light emitting diode devices comprising these compounds are also described.

Metal Complexes of Cyclometallated Imidazo[1,2-f]phenanthridine and Diimidazo[1,2-a:1',2'-c]quinazoline Ligands and Isoelectronic and Benzannulated Analogs Thereof

By doping an organic compound functioning as an electron donor (hereinafter referred to as donor molecules) into an organic compound layer contacting a cathode, donor levels can be formed between respective LUMO (lowest unoccupied molecular orbital) levels between the cathode and the organic compound layer, and therefore electrons can be injected from the cathode, and transmission of the injected electrons can be performed with good efficiency. Further, there are no problems such as excessive energy loss, deterioration of the organic compound layer itself, and the like accompanying electron movement, and therefore an increase in the electron injecting characteristics and a decrease in the driver voltage can both be achieved without depending on the work function of the cathode material.

Light Emitting Device

A material for organic EL's which is suitable for use as a luminescent-layer material giving an organic EL element less apt to suffer the deterioration in luminance caused by long-term operation and excellent in durability. The aluminum chelate complex for organic EL materials is an aluminum chelate complex which is represented by the general formula (1) and in which the amount of the compound represented by the general formula (1) wherein Ar2 is a halogen, as an impurity, is 350 wt.ppm or smaller. (1) In the formula, Ar1 represents mono- or bicyclic arylene; Ar2 represents mono- or bicyclic aryl; and R1 to R6 each represents hydrogen or a C1-8 hydrocarbon group. Incidentally, the impurity is the compound in which Ar2 is a halogen.

Aluminum chelate complex for organic el material

We have developed high-efficiency, long-lived organic light-emitting diode (OLED) devices by introducing red phosphorescent dopants into bis(8-quinolinolato)phenolato-aluminum(III) complexes. The devices exhibited luminance efficiency of 12 cd/A at CIE color coordinates (0.65, 034). The luminance half-decay lifetime is expected to be over 30,000 hours at an initial luminance of 700 cd/m2. We have successfully incorporated these devices into commercial OLED displays.

23.3: Distinguished Paper: Red‐Phosphorescent OLEDs Employing Bis(8‐Quinolinolato)‐Phenolato‐Aluminum(III) Complexes as Emission‐Layer Hosts

— We have used bis(8-quinolinolato)phenolato-aluminum complexes as emission-layer hosts in red-phosphorescent OLED devices. This enabled high-efficiency long-lived OLED devices with a simple device structure that does not require a hole-blocking layer. Devices with a red-phosphorescent dopant introduced into a noble bis(8-quinolinolato)phenolato-aluminum complex exhibited a high efficiency of 12 cd/A at CIE color coordinates (0.65, 035) and a long operating lifetime of 30,000 hours or more at an initial luminance of 700 cd/m2. Moreover, triplet-triplet annihilation was reduced in the devices because of the wide emission zone enabled by the complex and the short phosphorescent lifetime of the red-phosphorescent dopant. We have successfully incorporated these red-phosphorescent devices into commercial OLED displays.

Hiroshi Miyazaki

Papers

Aluminum chelate complex for organic el material

23.3: Distinguished Paper: Red‐Phosphorescent OLEDs Employing Bis(8‐Quinolinolato)‐Phenolato‐Aluminum(III) Complexes as Emission‐Layer Hosts

Red‐phosphorescent OLEDs employing bis(8‐quinolinolato)phenolato‐aluminum(III) complexes as emission‐layer hosts