Multilayered DNA Complex/Azo-Carbazole Films for Enhanced Holographic Recording

Azobenzene-based hologram recording materials are well known for their rewritable and polarization-selective properties that enable polarization-multiplexed recording and high-density optical storage. High diffraction efficiency, longer retention time, and shorter response time are desirable for rewritable recording materials, but they always require a trade-off relationship. In this study, we show that by simply coating the Azobenzene-based film with multiple layers of a suitable material, these parameters can be improved simultaneously without compromise. Bilayer films and triple layer films were prepared by depositing a DNA–surfactant complex-based layer above and below the azobenzene-based poly(CACzE-MMA) copolymer layer. The hologram recording performance was evaluated in terms of the diffraction efficiency, photoresponse time, and retention behavior of the recorded gratings. Compared with monolayer copolymer films, the multilayer DNA–surfactant complex-based copolymer films exhibited enhanced diffraction efficiency and faster photoresponse. In particular, the bilayer and trilayer structures showed a marked improvement in retention time, indicating suppressed relaxation of refractive index modulation. This enhancement is attributed to molecular confinement at the DNA–surfactant complex and copolymer interfaces generated by the layered architecture. These results demonstrate that a DNA–surfactant complex-based layering approach is an effective strategy for improving hologram stability and highlight the potential of DNA–surfactant complex-derived matrices as effective alternatives to poly(methyl methacrylate) (PMMA) in holographic applications.