Highly efficient non-doped OLEDs using aggregation-induced delayed fluorescence materials based on 10-phenyl-10H-phenothiazine 5,5-dioxide derivatives

Abstract

A novel electron acceptor based on 10-phenyl-10H-phenothiazine 5,5-dioxide (2PTO) was introduced for the first time to construct aggregation-induced delayed fluorescence materials. The emitter PXZ2PTO contains phenoxazine as the electron donor, exhibiting both AIE characteristics and TADF properties. Due to the highly stereoscopic structure and small ΔE_ST of PXZ2PTO, a green non-doped TADF OLED realized a high maximum EQE, CE and PE of 16.4%, 44.9 cd A⁻¹ and 32.0 lm W⁻¹, respectively, without using any optical outcoupling technology, which is comparable with the best reported non-doped TADF OLEDs. In addition, the efficiency of the non-doped devices are comparable with that of doped PXZ2PTO devices, with the maximum EQE, CE and PE of 16.3%, 43.8 cd A⁻¹ and 35.2 lm W⁻¹, respectively.