Creation of High-Quality Deep-Blue AIE Emitter with a Crossed Long-Short Axis Structure for Efficient and Versatile OLEDs.

Developing deep-blue emitters for organic light-emitting diodes (OLEDs) is critical but challenging, which requires a good balance between light color, exciton utilization, and photoluminescence quantum yield (PLQY) of solid film. Herein, a high-quality deep-blue emitter, abbreviated 2TriPE-CzMCN, is designed by introducing an aggregation-induced emission (AIE) group into a crossed long-short axis (CLSA) skeleton. Theoretical and experimental investigations reveal that the CLSA molecular design can achieve a balance between deep-blue emission and triplet-excitons utilization, while the high PLQY of the solid film resulting from the AIE feature helps to improve the performance of OLEDs.

Rational Medium-Range Charge Transfer Strategy Toward Highly Efficient Violet-Blue Organic Light-Emitting Diodes with Narrowed Emission.

The spectral narrowing engineering of pure-organic emitters attracts great research interests in realizing high color purity. Here, the adjusted medium-range charge transfer (MCT) strategy of TIC-BO with rigid planar structure by fusing two typical UV-emitting multiple resonance (MR) fragments via the ingenious double-halide cyclized coupling reaction is reported. The resulting TIC-BO with MCT nature shows efficient violet-blue emission in dilute toluene and evaporated host-guest films, and desirably narrowed spectra are achieved by the suppression of structural relaxation and the shortened charge transfer states.

An Ultraviolet Fluorophore with Narrowed Emission via Coplanar Molecular Strategy.

Narrowband emitting fluorophores exhibit immense potentials for organic light-emitting diodes (OLEDs) with high color purity. However, it's still hard to simultaneously realize short-wavelength ultraviolet (UV) or near ultraviolet emission (NUV) while maintaining a narrowed full width at half maximum (FWHM) value, and rare work focus on such challenging pursuit. Herein, an ingenious synthetic method was devised to achieve emitters with coplanar structure.

New-Fashioned Universal and Functional Host-Material from a Near-Ultraviolet Organic Emitter for High-Efficiency Organic Light-Emitting Diodes with Low Efficiency Roll-Offs.

In this work, a near-ultraviolet (NUV) emitter, 2MCz-CNMCz, with hot-exciton property is designed based on a "long-short axis" strategy, which exhibits good thermal stability, bipolar carrier transport ability, and high T energy level. Its nondoped NUV organic light-emitting diode (OLED) achieves a record maximum external quantum efficiency (η ) of 7.76%, with a peak at 404 nm and CIE coordinates of (0.