Organic photovoltaic (OPV) technology has been intensively investigated over the last decades as it represents an intriguing alternative for electrical power generation. Nevertheless, its market penetration is limited not so much by the lower power conversion efficiencies, but rather by the use of halogenated organic solvents, which are toxic and harmful (1,2). Polymer-based water-processable nanoparticles (WPNPs) represent a way to overcome the problem. They received considerable attention in the OPV field because their morphology can be modulated in order to optimize the interpenetrating electron donor/acceptor networks and thus to improve the device performance (3,4). Usually, WPNP dispersions are obtained through miniemulsion method using huge amount of surfactants. This approach makes it possible to reduce hazardous solvents in the active layer fabrication, increasing the sustainability of the process. However, surfactants display an insulating behaviour and have to be removed (5). Recently our research group developed the preparation of polymer-based WPNPs dispersions through miniemulsion approach using amphiphilic rod-coil block copolymers (ABCPs), bearing a rigid block (a p-type semiconducting polymer) and a hydrophilic flexible segment. Amphiphilic rod-coil block copolymers are able to self-assemble, generating organized nanostructures under specific conditions (6). The hydrophilic flexible block works as surfactant, interacting with aqueous medium and thus assuring the colloidal suspension stability (7). In addition, it interacts with the electron acceptor material (n-type), leading to the formation of pre-aggregated domains, whose dimensions are comparable with the exciton diffusion length. ABCP series, PCPDTBT-b-P4VP, were synthetized constituted by a low band gap copolymer (LBG), PCPDTBT as rod, and tailored segments of poly-4-vinylpyridine (P4VP) as hydrophilic flexible coil. Furthermore, their ability to form WPNP dispersion in aqueous medium through miniemulsion approach, neat or in blend with fullerene derivatives, was investigated. The so-obtained WPNPs were optically, morphologically and electrically characterized, and were tested as active layer in sustainable polymeric solar cells (8). We are developing new series of LBG-based WPNP dispersions in order to enhance the solar radiation absorption. Materials characterized by a higher degree of crystallinity have been selected to investigate the nanoscale structural organization of the p-type material inside the so-obtained WPNPs. References: 1. F. Marchui, D. Lenssen, M. Legros, S. Nordman, F. C. Krebs, Energy Environ. Sci. 2014, 7, 2792. 2. E. M. Ward, P. A. Shulte, T. Sorahan, G. Stevens, L. Zeise, V. J. Cogliano, Environ. Health Persp. 2010, 118, 1355. 3. M. C. Scharber, N.S. Sariciftci, Prog. Pol. Sci. 2013, 38, 1929. 4. N. P. Holmes, X. Zhou, M. R. Andersson, P. C. Dastoor, Nano Energy 2016, 19, 495. 5. S. Zhang, L. Ye, H. Zhang, J. Hou, Materials Today, 2016, 19, 533. 6. S. Zappia, R. Mendichi, S. Battiato, G. Scavia, R. Mastria, F. Samperi, S. Destri, Polymer, 2015, 80, 245. 7. doi.org/10.1016/j.polymer.2019.04.055. 8. S. Zappia, G. Scavia, A.M. Ferretti, U. Giovanella, V. Vohra, S. Destri, Adv Sustainabl Syst, 2018, 2, 1700155.
Water-processable blend nanoparticles for sustainable organic solar cells
2019
Abstract
Organic photovoltaic (OPV) technology has been intensively investigated over the last decades as it represents an intriguing alternative for electrical power generation. Nevertheless, its market penetration is limited not so much by the lower power conversion efficiencies, but rather by the use of halogenated organic solvents, which are toxic and harmful (1,2). Polymer-based water-processable nanoparticles (WPNPs) represent a way to overcome the problem. They received considerable attention in the OPV field because their morphology can be modulated in order to optimize the interpenetrating electron donor/acceptor networks and thus to improve the device performance (3,4). Usually, WPNP dispersions are obtained through miniemulsion method using huge amount of surfactants. This approach makes it possible to reduce hazardous solvents in the active layer fabrication, increasing the sustainability of the process. However, surfactants display an insulating behaviour and have to be removed (5). Recently our research group developed the preparation of polymer-based WPNPs dispersions through miniemulsion approach using amphiphilic rod-coil block copolymers (ABCPs), bearing a rigid block (a p-type semiconducting polymer) and a hydrophilic flexible segment. Amphiphilic rod-coil block copolymers are able to self-assemble, generating organized nanostructures under specific conditions (6). The hydrophilic flexible block works as surfactant, interacting with aqueous medium and thus assuring the colloidal suspension stability (7). In addition, it interacts with the electron acceptor material (n-type), leading to the formation of pre-aggregated domains, whose dimensions are comparable with the exciton diffusion length. ABCP series, PCPDTBT-b-P4VP, were synthetized constituted by a low band gap copolymer (LBG), PCPDTBT as rod, and tailored segments of poly-4-vinylpyridine (P4VP) as hydrophilic flexible coil. Furthermore, their ability to form WPNP dispersion in aqueous medium through miniemulsion approach, neat or in blend with fullerene derivatives, was investigated. The so-obtained WPNPs were optically, morphologically and electrically characterized, and were tested as active layer in sustainable polymeric solar cells (8). We are developing new series of LBG-based WPNP dispersions in order to enhance the solar radiation absorption. Materials characterized by a higher degree of crystallinity have been selected to investigate the nanoscale structural organization of the p-type material inside the so-obtained WPNPs. References: 1. F. Marchui, D. Lenssen, M. Legros, S. Nordman, F. C. Krebs, Energy Environ. Sci. 2014, 7, 2792. 2. E. M. Ward, P. A. Shulte, T. Sorahan, G. Stevens, L. Zeise, V. J. Cogliano, Environ. Health Persp. 2010, 118, 1355. 3. M. C. Scharber, N.S. Sariciftci, Prog. Pol. Sci. 2013, 38, 1929. 4. N. P. Holmes, X. Zhou, M. R. Andersson, P. C. Dastoor, Nano Energy 2016, 19, 495. 5. S. Zhang, L. Ye, H. Zhang, J. Hou, Materials Today, 2016, 19, 533. 6. S. Zappia, R. Mendichi, S. Battiato, G. Scavia, R. Mastria, F. Samperi, S. Destri, Polymer, 2015, 80, 245. 7. doi.org/10.1016/j.polymer.2019.04.055. 8. S. Zappia, G. Scavia, A.M. Ferretti, U. Giovanella, V. Vohra, S. Destri, Adv Sustainabl Syst, 2018, 2, 1700155.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
