Project R-13038

Organic spintronics based on intrinsically paramagnetic polymers. (Research)

The weak spin-orbit interaction inherent to organic semiconductors makes them ideal candidates for spintronics applications. While typical spin lifetimes easily surpass those of their inorganic counterparts by several orders of magnitude, the main limitation in organic spin transporters is the spin diffusion length, often not exceeding 50 nm. It has now been established that spins in organic materials can be transported either by mobile charges or via spin exchange between localized polarons. The latter mechanism opens up an interesting new avenue toward longer spin diffusion lengths by increasing the intrinsic spin density of the materials. In 2019, record spin diffusion lengths of 1 um have been reported for the first time in a highly-doped polymer. In this project, I propose to investigate spin transport in paramagnetic polymers, a recently-discovered class of ultra-low-bandgap semiconductors exhibiting a triplet ground state and hence a large intrinsic spin density. Spin transport experiments will be performed in state-of-the-art spintronic devices based on spin pumping injection. In addition, the combination of electron paramagnetic resonance methods and supporting quantum-chemical computations will provide detailed information on spin delocalization and spin-spin-interactions. By expanding my study to a series of these polymers, structureproperty relations can be elucidated and used to establish the fundamentals of spin transport in these innovative materials

01 November 2022 - 31 October 2025