Enhanced Photorefractive Performance by Controlling Ion‐Assisted Charge Injection and Accumulation with Random Biphenyl Co‐Polymerized Poly(Carbazolyl‐Amine)

In this study, the synthesis of poly(carbazolyl‐amine)s with a random co‐polymerized biphenyl group through the Buchwald–Hartwig amination to enhance ion‐assisted space‐charge‐limited current (SCLC) and achieve efficient performance in photorefractive (PR) polymers, is reported. By modulating the polymer crystallinity, the efficient accumulation of ions near an electrode is achieved and enhanced ion‐assisted SCLC is realized, which results in a magnified electric field inside the polymers. The internal electric field is increased by the stacked charges injected from the electrode, and it is further enhanced by the washing out of ions. The polymer, blended with the electro–optical chromophore and sensitizer, exhibits a high PR sensitivity of 16.7 cm 3 kJ −1 and a device stability of up to E = 80 V µm −1 at a wavelength of 633 nm, which is comparable to that of the inorganic crystals Bi 12 SiO 20 and Sn 2 P 2 S 6 .