Synergistic Enhancement of Luminescent and Ferroelectric Properties through Multi‐Clipping of Tetraphenylethenes

Abstract

Synergistically enhancing luminescent and ferroelectric (SELF) properties are observed from a tetraphenylethene (TP) substituted with clipping groups (C), where the C is consisting of a 4-[3,5-bis-(3-decyloxy-styryl)-styryl]-phenyl (DOS) unit. The DOS units of TPCn are self-assembled via intermolecular interaction to clip themselves and induce TP aggregation, as evidenced by clip-induced quenching of emission at DOS units (E clip ) accompanied by aggregation-induced emission enhancement of TPs (E AIE ). TPC4 demonstrates strong photoluminescence in a dilute chloroform solution and large E AIE in aqueous (>50%) THF solution. TPCn demonstrates SELF properties in film state, with high quantum yields of photoluminescence (>80%) and ferroelectric switching. Due to the introduction of four clips, TPC4 has a higher remnant polarization (P r = 2.27 µC cm −2 ) at room temperature than TPC1. TPC4 is successfully employed in a light-emitting electrochemical cell to achieve over 1290 cd m −2 under pulsed current conditions. The TPC4 film on a flexible substrate produced a piezoelectric output voltage of up to 0.13 V and a current density of 1.14 nA cm −2 upon bending. These results indicate that the side chain clipping and TP aggregation resulted in unprecedented flexible SELF properties in a single compound, offering simultaneous enhancement of electroluminescence, mechanical sensitivity, and energy harvesting capacity.

Synergetic ferroelectric luminescence from self-assembled tetraphenylethene aggregates

“…SFL materials (TPCn) were synthesized using Wittig-Hörner reaction by reacting benzo-formyl substituted TPEs with SAGs in anhydrous tetrahydrofuran and sodium tert-butoxide (Figure 1a). 3 The UV-Vis absorption spectra of the SFL materials in chloroform showed a maximum peak at 320 -326 nm (Figure 1b).…”