Trefoil-shaped monomer with carbazole-functionalized triazine core for high-performance multi-electrochromic polymer films and devices

The structural architecture of a material plays an important role in tailoring its electrical, mechanical, and optical properties. One of the most effective, simple, and rational approaches used in molecular design is the synthesis of monomers having three carbazole units attached to the s-triazine nucleus. Herein, we mainly highlight the design and synthesis of a novel three-armed trefoil-shaped monomer (N-2,N-4,N-6-tris(4-(4-(9H-carbazol-9-yl)butoxy)phenyl)-1,3,5-triazine-2,4,6-triamine). The 3-TCN encoded trefoil-shaped monomer has been electropolymerized by using the cyclic voltammetry (CV) method in a 0.1 M TBAPF(6)/DCM electrolyte solution. The surface morphology results showed a microporous structure, which can be attributed to the high electrical and optical performances of the polymer film. The cross-linked polymer with three-dimensional charge transport has been found to have improved optical and electrical properties with excellent optical contrast, fast switching time, and long-term stability. The obtained P3-TCN polymer film has exhibited multi-electrochromic properties with color diversity of transparent, yellow, green, and dark green under different applied potentials. High-performance P3-TCN polymer film could be used as an anodic coloring component in the construction of smart windows. Based on this, the solid-state electrochromic device (ECD) consisting of P3-TCN and PEDOT has been fabricated, and its opto-electrical properties have been characterized.