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Dynamic spin filtering at the Co/Alq3 interface mediated by weakly coupled second layer molecules
Andrea Droghetti1,2, Philip Thielen3,4, Ivan Rungger1,5
1School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland.
Nature Communications
|September 1, 2016
Summary
This study reveals a novel spin filtering mechanism at organic-metal interfaces. It uses dynamical spin relaxation in interface states to control spin-polarized carrier injection for molecular spintronics.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Organic Electronics
Background:
- Spin filtering at organic-metal interfaces is crucial for molecular spintronics.
- Interface interactions between organic molecules and magnetic electrodes dictate spin selectivity.
Purpose of the Study:
- To demonstrate a new spin-filtering mechanism.
- To investigate spin dynamics at Alq3/Co interfaces.
- To understand the role of interface states and molecular layers in spin transport.
Main Methods:
- Combined two-photon photoemission experiments and electronic structure theory.
- Investigated Alq3 (tris(8-hydroxyquinolinato)aluminum) on Cobalt (Co) interfaces.
- Analyzed long-time spin-dependent electron dynamics.
Main Results:
- Identified a spin-filtering mechanism based on dynamical spin relaxation of interface states.
- Observed that molecules in the second organic layer drive spin-dependent electron dynamics.
- Interface states are not spin-split but exhibit spin-dependent lifetimes due to Co substrate interaction.
Conclusions:
- Dynamical spin relaxation in interface states provides a viable spin-filtering mechanism.
- This mechanism is key for spin-polarized carrier injection and diffusion in molecular spintronics devices.
- The findings offer new pathways for designing advanced spintronic components.
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