Manipulating exciton dynamics of thermally activated delayed fluorescence materials for tuning two-photon nanotheranostics.

Rational manipulation of energy utilization from excited-state radiation of theranostic agents with a donor-acceptor structure is relatively unexplored. Herein, we present an effective strategy to tune the exciton dynamics of radiative excited state decay for augmenting two-photon nanotheranostics. As a proof of concept, two thermally activated delayed fluorescence (TADF) molecules with different electron-donating segments are engineered, which possess donor-acceptor structures and strong emissions in the deep-red region with aggregation-induced emission characteristics.

The Nanoassembly of an Intrinsically Cytotoxic Near-Infrared Dye for Multifunctionally Synergistic Theranostics.

The combination of diagnostic and therapeutic functions in a single theranostic nanoagent generally requires the integration of multi-ingredients. Herein, a cytotoxic near-infrared (NIR) dye (IR-797) and its nanoassembly are reported for multifunctional cancer theranostics. The hydrophobic IR-797 molecules are self-assembled into nanoparticles, which are further modified with an amphiphilic polymer (C18PMH-PEG5000) on the surface.

Efficient Orange-Red Thermally Activated Delayed Fluorescence Emitters Feasible for Both Thermal Evaporation and Solution Process.

Development of red thermally activated delayed fluorescence (TADF) emitters has been lagging behind when compared with those of blue and green fluorophores, especially for solution-processable ones. In this work, two novel orange-red TADF emitters 3,6-di(10-phenoxazin-10-yl)dibenzo[,]phenazine (DBPZ-DPXZ) and 10,10'-(11,12-bis(3,5-di--butylphenyl)dibenzo[,]phenazine-3,6-diyl)bis(10-phenoxazine) (DBBPZ-DPXZ) are developed. A high-performance orange-red TADF emitter, DBPZ-DPXZ, is first prepared by connecting a rigid acceptor and two rigid donor segments.

Red/Near-Infrared Thermally Activated Delayed Fluorescence OLEDs with Near 100 % Internal Quantum Efficiency.

Developing red thermally activated delayed fluorescence (TADF) emitters, attainable for both high-efficient red organic light-emitting diodes (OLEDs) and non-doped deep red/near-infrared (NIR) OLEDs, is challenging. Now, two red emitters, BPPZ-PXZ and mDPBPZ-PXZ, with twisted donor-acceptor structures were designed and synthesized to study molecular design strategies of high-efficiency red TADF emitters. BPPZ-PXZ employs the strictest molecular restrictions to suppress energy loss and realizes red emission with a photoluminescence quantum yield (Φ ) of 100±0.

Red Organic Light-Emitting Diode with External Quantum Efficiency beyond 20% Based on a Novel Thermally Activated Delayed Fluorescence Emitter.

A novel thermally activated delayed fluorescence (TADF) emitter 12,15-di(10-phenoxazin-10-yl)dibenzo[,]dipyrido[3,2-:2',3'-]phenazine (DPXZ-BPPZ) is developed for a highly efficient red organic light-emitting diode (OLED). With rigid and planar constituent groups and evident steric hindrance between electron-donor (D) and electron-acceptor (A) segments, DPXZ-BPPZ realizes extremely high rigidity to suppress the internal conversion process. Meanwhile, the highly twisted structure between D and A segments will also lead to an extremely small singlet-triplet energy split to DPXZ-BPPZ.