Achieving Long Spin Diffusion Lengths in Carbon-based Semiconductors

ISMC2019 plenary talks were held in the impressive McEwan Hall. Copyright: University of Edinburgh, Paul Maguire
ISMC2019: Spectacular Settings in Edinburgh
31st July 2020
Schematic representation of the tube dilation in linear-linear and star-linear blends. The undilated tube has a diameter and increases with time as a consequence of constraint release (CR) – relaxation of a given chain driven by the motions of surrounding chains. Copyright: University of the Basque Country
Direct Observation of Tube Dilation in Polymer Blends
3rd August 2020

Carbon-based semiconductors such as conjugated organic polymers are of potential use in the development of spintronic devices and spin-based information processing. In particular, these materials offer a low spin–orbit coupling strength due to their relatively light constituent chemical elements, which should, in principle, favour long spin diffusion lengths.

However, organic polymers are relatively disordered materials and typically have a carrier mobility that is orders of magnitude lower than crystalline inorganic materials. As a result, small spin diffusion lengths of around 50 nm have typically been measured using vertical organic spin valves. Here, we report measuring spin diffusion lengths in doped conjugated polymers using a lateral spin transport device architecture, which is based on spin pumping injection and inverse spin Hall detection.

The approach suggests that long spin diffusion lengths of more than 1 μm and fast spin transit times of around 10 ns are possible in conjugated polymer systems when they have a sufficiently high spin density (around 1020 cm-3). We explain these results in terms of an exchange-based spin diffusion regime in which the exchange interactions decouple spin and charge transport.

Read more: 
Wang S.-J. et al., Nat. Electr. 2, 98 (2019)

SoftComp partner:
University of Mainz



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