A Hybrid BN-doped nanographene with narrow emission bandwidths for OLEDs.

We describe synthesis of BN-doped nanographene containing five phenylene units, boron and nitrogen atoms with both alternating ortho-disposition as well as direct B-N connection. Resulting BN doped nanographene exhibits blue fluorescence at 441 nm with extraordinary narrow fluorescence peak with full width at half maximum (FWHM) = 10-11 nm. Crystallography reveals supramolecular organization of this compound in the crystal phase.

Triplet-triplet annihilation in highly efficient fluorescent organic light-emitting diodes: current state and future outlook.

Studies of delayed electroluminescence in highly efficient fluorescent organic light-emitting diodes (OLEDs) of many dissimilar architectures indicate that the triplet-triplet annihilation (TTA) significantly increases yield of excited singlet states-emitting molecules in this type of device thereby contributes substantially to their efficiency. Towards the end of the 2000s, the essential role of TTA in realizing highly efficient fluorescent devices was widely recognized. Analysis of a diverse set of fluorescent OLEDs shows that high efficiencies are often cor-related to TTA extents.

E-type delayed fluorescence of a phosphine-supported Cu2(mu-NAr2)2 diamond core: harvesting singlet and triplet excitons in OLEDs.

A highly emissive bis(phosphine)diarylamido dinuclear copper(I) complex (quantum yield = 57%) was shown to exhibit E-type delayed fluorescence by variable temperature emission spectroscopy and photoluminescence decay measurement of doped vapor-deposited films. The lowest energy singlet and triplet excited states were assigned as charge transfer states on the basis of theoretical calculations and the small observed S(1)-T(1) energy gap. Vapor-deposited OLEDs doped with the complex in the emissive layer gave a maximum external quantum efficiency of 16.

Degradation mechanisms in small-molecule and polymer organic light-emitting diodes.

Degradation in organic light-emitting diodes (OLEDs) is a complex problem. Depending upon the materials and the device architectures used, the degradation mechanism can be very different. In this Progress Report, using examples in both small molecule and polymer OLEDs, the different degradation mechanisms in two types of devices are examined.