Triarylamine‐Based Wholly Aromatic Polyimide with Simultaneously Unprecedented Photoluminescence Efficiency and High Glass‐Transition Temperature

Abstract The weak photoluminescence (PL) of wholly aromatic polyimide (Ar‐PI) is generally associated with the strong charge‐transfer complex effect in both solution and solid states. Research has focused on structural designs promoting the PL behavior, but Ar‐PI PL remains a challenge in the solid state. Herein, a twisted conformation is incorporated into a triphenylamine‐based polyimide backbone to obtain a series of Ar‐PIs with extremely high PL quantum efficiency (Φ_PL) in solution and even film states. PI3M‐4M exhibits the highest Φ_PL of up to 61% in the film state, which is considerably superior to the values for reported Ar‐PIs. PI3M‐4M is also the first Ar‐PI to simultaneously demonstrate an unprecedented Φ_PL with a remarkable glass‐transition temperature T_g of 470 °C.