Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV18)
Publication date: 21st February 2018
Advances in the development of non-fullerene electron acceptors such as indaceno[1,2-b:5,6-b']dithiophene (IDT)-based small molecules have made fullerene-free organic solar cells to a competitive alternative to conventional fullerene-based organic photovoltaics with efficiencies approaching 13%.[1] Despite the recent progress and enormous potential of non-fullerene organic solar cells (NF-OSCs), the influence of the polymers molecular weight on the performance and structure-property relationship of polymer:small molecule bulk-heterojunction systems has not been studied in detail so far, even though this could play a key role to further improve the efficiency.
For this purpose, we systematically investigated the effect of the polymers molecular weight on the photovoltaic performance, film morphology, charge carrier mobility and non-geminate recombination dynamics of NF-OSCs using the low bandgap polymer PTB7-Th (with molecular weights in the range of 50-300 kDa) and the small molecule O-IDTBR (O = n-octyl) as donor and acceptor species, respectively. Inverted bulk-heterojunction solar cells with an open-circuit voltage of about 1 V, a short-circuit current density of ca. 15.2 mA cm−2, a fill factor over 60%, and a power conversion efficiency of 10% were obtained using high molecular weight polymers. The photovoltaic performance, however, was significantly influenced by the different molecular weight of PTB7-Th exhibiting an optimum at 200 kDa. This can be correlated with the improved field-effect hole mobility (ca. 1.1 × 10−2 cm2 V−1 s−1) and the lower activation energy of charge transport (25 meV) of PTB7-Th. Further considerable contributions originate from the favorable film morphology and phase separation, the higher degree of crystallinity (π−π stacking of polymer backbone), the higher charge carrier concentration and lifetime (4.5 µs) as well as the lower non-geminate recombination rate constant.
[1] Zhao et al., J. Am. Chem. Soc. 2017, 139, 7148-7151.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.