Use of a Ruthenium-Containing Conjugated Polymer as a Photosensitizer in Photovoltaic Devices Fabricated by a Layer-by-Layer Deposition Process

Abstract

Multilayer polymer films composed of a ruthenium terpyridine complex containing poly(p-phenylenevinylene) (Ru-PPV) and sulfonated polyaniline (SPAN) were prepared by a layer-by-layer electrostatic self-assembly deposition. The deposition process was carried out from SPAN solution in water and Ru-PPV in dimethylformamide (DMF). Optical-quality multilayer thin films were obtained. The film growth process was monitored by quartz crystal microbalance, and the surface morphology of the films was studied by atomic force microscopy. It was found that the properties of the multilayer films were dependent on deposition conditions such as the pH of the SPAN solution, the presence of salt in the polymer solutions, and the post-film-forming thermal annealing process. Cross-section transmission electron microscopic images suggested that there was no stratified structure formed in the multilayer films. Photovoltaic cells were fabricated by sandwiching the multilayer films between indium-tin-oxide and aluminum electrodes. The device performances were examined by illumination with AM 1.5 simulated solar light. The power conversion efficiencies of these devices were on the order of 10(-3)%. The maximum incident photon-to-electron conversion efficiency (IPCE) of the devices was found to be approximately 2% at 510 nm, which is consistent with the absorption maximum of the ruthenium complex. This indicates that the photosensitization process is due to the electronic excitation of the ruthenium complex.

Design of Multilayered Nanostructures and Donor–Acceptor Interfaces in Solution‐Processed Thin‐Film Organic Solar Cells

“…10 nm by the layer-by-layer deposition technique, which distinguishes it from previous approaches in which all functional layers were prepared by layer-by-layer deposition. [29][30][31][32] Indeed, FF of our devices decreased to less than 0.25 when the light-harvesting layer was thicker than 30 nm. We should note that our devices were fabricated in air with wet processes and their J-V characteristics were also measured in air.…”

“…Thus, thin-film organic solar cells that utilize these advantages of the layer-by-layer technique have been reported by some groups. [29][30][31][32][33][34] However, it has not been fully exploited in organic solar cells to date and the performance of the devices has remained poor, with a low power conversion efficiency of <0.05%, partly because of the low charge mobility. [33] Recently, we reported an improvement in conductive and photovoltaic properties of a poly( p-phenylenevinylene) (PPV)-based layer-by-layer thin-film device by low-temperature conversion.…”

Comparison of permeability of poly(allylamine hydrochloride)/and poly(diallyldimethylammonium chloride)/poly(4-styrenesulfonate) multilayer films: Linear vs. exponential growth

“…The potential applications of these films include selective membranes [3], conducting layers [4], biosensors [5], drug-delivery systems [6] or biomaterials [7]. The simplicity of fabrication makes polyelectrolyte films also potent candidates as materials for photovoltaic [8] and fuel cells [9]. Since the only precondition for the formation of multilayers is the presence of charge, films can be built at any surface from variety of nanocomponents, such as: polyelectrolytes, metallic, oxide or polymer nanoparticles, delaminated clay platelets [10].…”

Electroluminescent characteristics of spin-assembled multilayer films with confined layer structure

“…Recently, there has been considerable interest in the Layerby-Layer assembly method based on dipping process (i.e., dipassembly method) because of its ability to control the film thickness at a molecular level with the facile insertion of various materials [1][2][3][4][5]. An important advantage of this method is that it enables the preparation of films with controlled thickness, composition and functionality on substrates of different size and shape [1][2][3][4][5].…”

“…An important advantage of this method is that it enables the preparation of films with controlled thickness, composition and functionality on substrates of different size and shape [1][2][3][4][5]. Additionally, various organic components can be inserted within dip-assembled films through complementary interactions (i.e., electrostatic, hydrogen-bonding or covalent interaction).…”