Supra spin-selection · Spin-Selection using Chirality: A Supramolecular Approach
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2016-03-01 → 2018-02-28
- EU contribution
- €177,599
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
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Results in brief
Spin-Selection using Chirality: A Supramolecular Approach
In recent times there is an impetus towards more sustainable and efficient ways of living, with an aim to lowering our dependence on non-renewable resources of energy. We are increasingly using electronic gadgets with advanced features, better contrast and smart lighting technologies. Prime examples are the use of light-emitting diodes (LEDs) over incandescent bulbs and LED displays over conventional liquid crystal displays. Many of the LED devices now-a-days make use of organic based materials because of the lower cost and flexibility to adopt on surfaces of different topologies. However, still the performance of these materials is not comparable to those of well-established inorganic materials. Thus, there is a need for new innovative concepts to realize efficient devices with organic materials. One of the new concepts (CISS effect) developed by Naaman and Waldeck harnesses spin of chiral organic or soft materials to achieve efficient OLEDs. However, only proof-of-concept studies have been carried out so far and this idea has not yet been applied to organic systems which can transport charges to realize its full potential in OLEDs. In the current project, such an effort was undertaken and a summary of the results are presented below. The CISS effect was successfully tested on a state-of-the-art organic polymer with high chiral organization in an OLED architecture. However, the efficiency of the effect was low (~5%). In order to further increase the efficiency, a new, generally applicable and practical approach was developed to improve the chiral organization of polymeric systems. In addition, control over the chiral organization of such systems was demonstrated using light as a stimuli to control the device performances.
Data: CORDIS, © European Union
Project objective
Organic electronics which exploits charges (electrons or holes) of π-conjugated molecules/polymers has garnered attention in the past decade due to the low cost, ease of processability and most importantly the flexibility to tune the electronic properties through chemical synthesis. In addition to charge, spin as a quantum number provides exciting opportunities to store data in memory devices, in spin filters and spin-based organic light-emitting diodes. Typically in spintronic devices, switching of the magnetism of one of the ferromagnetic layers is required to attain spin-selectivity. Recent works have demonstrated high (>60%) spin-selectivity in organized chiral double-stranded deoxyribonucleic acid (DNA) without the use of magnetic materials. The high spin-selectivity was attributed to the creation of chiral field in which the electron-transport takes place through DNAs. It is to be noted that the organization of DNA strands is pivotal in achieving high spin-selectivity. Presently, the main focus is on bio-inspired molecules such as peptides and DNAs. Due to the versatility and processability of organic semiconductors, they are ideal candidates for obtaining chiral electron flow leading to functional organic spintronic devices without ferromagnets. Thus the present proposal aims at design, synthesis and characterization of chiral π-conjugated oligomers and polymers with ordered supramolecular organization on surfaces as testbeds for spin-selective electron transport. Chiral fluorene oligomers/polymers are known to form cholesteric liquid crystal phases on surfaces. Based on this, our design includes chiral fluorene based oligomers and polymers attached with pendant acid groups to anchor on surfaces to obtain chiral supramolecular organization desired for the electron-transport. This project will be the first demonstration of chiral-spin selectivity in synthetic self-assembled structures and will pave way for a plethora of spin-based applications.
Original text from CORDIS.
Participants
- TECHNISCHE UNIVERSITEIT EINDHOVEN · EindhovenCoordinatorNetherlands
Links
Data: CORDIS, © European Union