Highly efficient and stable deep-blue organic light-emitting diode using phosphor-sensitized thermally activated delayed fluorescence.

Phosphorescent and thermally activated delayed fluorescence (TADF) blue organic light-emitting diodes (OLEDs) have been developed to overcome the low efficiency of fluorescent OLEDs. However, device instability, originating from triplet excitons and polarons, limits blue OLED applications. Here, we develop a phosphor-sensitized TADF emission system with TADF emitters to achieve high efficiency and long operational lifetime.

Selective colorimetric sensing of anions in aqueous media through reversible covalent bonding.

Selective colorimetric sensing of anions in aqueous media has been studied, which involves reversible covalent bonding as key binding interactions. By introducing a simple nitro chromophore into an o-(carboxamido)trifluoroacetophenone ionophore that recognizes anions through reversible covalent bonding, we have realized a complete selectivity in colorimetric sensing of cyanide among competing anions such as fluoride, acetate, and dihydrogen phosphate in aqueous media. Such selectivity is explained by dominant reversible covalent bonding over hydrogen bonding, which leads to indirect internal charge transfer.