Proceedings of nanoGe Spring Meeting 2022 (NSM22)
DOI: https://doi.org/10.29363/nanoge.nsm.2022.223
Publication date: 7th February 2022
Organic thin films that emit and absorb circularly polarised (CP) light have been demonstrated with the promise of achieving important technological advances; from efficient, high-performance displays, to 3D imaging and all-organic spintronic devices. As a result, interest in the identification of materials that can emit CP light has surged in recent years. Unfortunately, the selectivity in absorption or emission (so-called dissymmetry or g-factor) of left-handed versus right-handed CP light is low for many molecular systems. Conjugated polymer thin films can give rise to very large dissymmetry (|gabs| >1).The precise origins of the large chiroptical effects in such films had, until recently, remained elusive. We have investigated the emergence of such phenomena in achiral polymers blended with chiral small-molecule additives and intrinsically chiral-sidechain polymers using a combination of spectroscopic methods and structural probes. We show that – under conditions relevant for device fabrication – the large chiroptical effects are caused by magneto-electric coupling (natural optical activity), not structural chirality as previously assumed, and may occur because of local order in a cylinder blue phase-type organisation and increased delocalisation of their chromophore/excitonic coupling. We show that optimised chiral polymer systems can be used as the active layers of CP Organic Photodetectors (OPDs) and CP Organic Light Emitting Diodes (OLEDs) with exceptional device performance. For example, CP OLEDs based on the widely studied π-conjugated polymer F8BT can achieve current efficiencies of 16.4 cd/A, power efficiency of 16.6 lm/W, a maximum luminance of over 28,500 cd/m2, and a high electroluminescence dissymmetry of 0.57, whilst CP OPDs achieve photocurrent dissymmetries of 0.85, low dark currents (10 pA) and ultrafast response times. Our disruptive mechanistic insight into chiral polymer thin films will offer new approaches towards the development of chiroptical materials and devices.
Professor Matthew Fuchter, Professor Alasdair Campbell, Dr Li Wan, Dr Matthew Ward, Dr Jochen Brandt
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.