Novel anisotropic ordered polymeric materials based on metallopolymer precursors as dye sensitized solar cells

Abstract

Developing molecular self-assembly is an important step to generate ordered nanostructure materials. In this pursuit, a simple template-free method is reported to develop anisotropic nanostructures using metallopolymer precursors. The phenanthroline-based ruthenium complex monomer (PDAR) and its polymers [3-armed PPDAR (PPDAR-3) and 4-armed PPDAR (PPDAR-4)] were synthesized using ATRP method. These materials displayed higher glass transition temperatures (182 °C for PPDAR-4 and 176 °C for PPDAR-3) compared to the linear polymer, PPDAR (144 °C). The materials showed metal-to-ligand charge transfer (MLCT) absorption peak at 440 nm and armed polymers exhibited higher molar absorption coefficient (PPDAR-4: 7.6 × 105 M−1 cm−1 and PPDAR-3: 6.58 × 105 M−1cm−1) compared to the linear polymer (4.6 × 105 M−1cm−1). The materials were self-assembled in the presence of non-polar solvents to form uniform nano-domain micelles. Thin films of these materials were formed and subjected to elevated annealing temperatures (180 °C) and were fully characterized by AFM, SEM, and XRD techniques to understand the mechanism of self-assembly. Furthermore, dye sensitized solar cell (DSSC) devices were fabricated using the materials as additional components of a liquid electrolyte (I3 −/I−) to explore the role of these architectures on open circuit voltage (VOC) as well as cell power conversion efficiency (PCE). Overall, this study provides new insights in the area of metallopolymers.