Ordered luminescent nanohybrid thin films of Eu(BA)3Phen nanoparticle in polystyrene matrix from diblock copolymer self-assembly

A simple route for fabricating highly ordered luminescent thin films based on hybrid material of diblockcopolymer and europium complex, assisted with self-organization of polystyrene-block-poly(ethyleneoxide) (PS-b-PEO) diblock copolymer upon solvent annealing, is presented. PS-b-PEO self-organized intohexagonal patterns and europium complex of Eu(BA)3Phen was selectively embedded in PS blocks aftersolvent annealing in benzene or benzene/water vapor. During benzene annealing, the orientation of thePEO cylindrical domains strongly depended on the Eu(BA)3Phen concentration. In contrast, when thehybrid thin filmswere annealed inmixture of benzene and water vapor, high degree of orientation of thePEO cylindrical domains is more easily obtained, which is independent of Eu(BA)3Phen concentration.Furthermore, preferential interaction of PEO domains with water induces a generation of nanopores inthe hybrid thin film. Atomic force microscopy (AFM), scanning electron microscopy (SEM), andtransmission electron microscopy (TEM) were used to characterize the long-range lateral order andphase composition of the hybrid thin films. The ordered nanohybrid thin films kept the fluorescenceproperty of Eu(BA)3Phen and showed a strong red emission under the 254 nm light’s irradiation. Thefluorescence property was confirmed by photoluminescence (PL) spectra.