Highly efficient blue all-solution-processed organic light-emitting diodes based on the strategy of constructing a thermally cross-linkable TADF dendrimer

Based on the strategy of constructing a new cross-linkable thermally activated delayed fluorescence TADF dendrimer act as the emitter, the blue all-solution-processed organic light-emitting diodes (OLEDs) was developed. Here, two thermally cross-linkable TADF molecules, namely DV-3CzCN and DVCz-3CzCN, are designed and synthesized. Systematic studies demonstrate that the utilization of DVCz-3CzCN can form a stable and uniform thin film by the solution-process, but also effectively suppress the triplet excitons concentration quenching by the intermolecular interaction. Simultaneously, DVCz-3CzCN possesses the sufficient solvent resistance that can afford the subsequently deposition of electron transporting materials by orthogonal solvent. Consequently, the highly efficient blue all-solution-processed device based on DVCz-3CzCN realized a maximum current efficiency (CE), power efficiency (PE) and external quantum efficiency (EQE) of 7.1 cd A−1, 4.5 lm W−1 and 6.8%, respectively, which is eight times higher in device efficiency than corresponding device with the unencapsulated DV-3CzCN.