A simple and effective strategy to lock the quasi-equatorial conformation of acridine by H-H repulsion for highly efficient thermally activated delayed fluorescence emitters.

A novel electron donor, namely, TMDBP is designed by angularly fusing two acridine moieties. The DMAC subunits in TMDBP exhibit a dominant quasi-equatorial conformation due to steric H-H repulsion. The new TADF emitters render excellent OLED performances with EQE up to 24.2% and small efficiency roll-off.

Fused twin-acridine scaffolds as electron donors for thermally activated delayed fluorescence emitters: controllable TADF behavior by methyl substitution.

Fused twin-acridine scaffolds of TMQAC and MeTMQAC were designed as novel donors to construct new organic emitters. TMQAC-based emitters were TADF active, while the TADF character was turned off in MeTMQAC-based emitters by the extra methyl group. The TMQAC-based emitters exhibited high OLED performances, with external quantum efficiencies (EQEs) of up to 20.7%.

Lithium vanadate nanowires@reduced graphene oxide nanocomposites on titanium foil with super high capacities for lithium-ion batteries.

With a theoretically high capacity and suitable discharge/charge plateaus, lithium vanadates (such as Li0.04V2O5) can be used as cathode material for lithium ion batteries. Herein, Li0.04V2O5 nanowires are densely anchored onto reduced graphene oxide (rGO) nanosheets to form a Li0.04V2O5@rGO nanocomposite by a hydrothermal method with subsequent thermal treatment. Due to this unique structure, the Li0.04V2O5@rGO exhibits remarkable rate performance and excellent cycling stability. Specifically, it delivers a reversible discharge capacity of 738.09mAhg-1 at a current density of 100mAg-1 in the voltage range of 2.0-4.0V. After 500 cycles, it still maintains a high capacity of 731.70mAhg-1, which represents 95.01% retention of the original reversible capacity. These results indicate that the Li0.04V2O5@rGO could be a promising candidate as cathode active material for long-term cycling performance in lithium-ion batteries.