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Spin-Dependent Ionization of Chiral Molecular Films
John M Abendroth1,2, Kevin M Cheung1,2, Dominik M Stemer1,3
1California NanoSystems Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States.
Journal of the American Chemical Society
|February 9, 2019
Summary
Spin-polarized electrons interact with chiral organic films, influencing photoemission. This study reveals how molecular structure and substrate magnetism affect electron spin selectivity and energy barriers.
Area of Science:
- Surface Science
- Spectroscopy
- Organic Electronics
Background:
- Ferromagnetic substrates functionalized with chiral organic films are key in spintronics.
- Understanding spin selectivity in photoemission is crucial for developing novel electronic devices.
Purpose of the Study:
- To analyze spin selectivity in photoemission from ferromagnetic substrates coated with chiral organic films.
- To investigate the influence of molecular structure and substrate magnetization on photoelectron properties.
Main Methods:
- Ultraviolet photoelectron spectroscopy (UPS) at room temperature.
- Analysis of photoelectrons originating from both ferromagnetic substrates and chiral organic films.
- Investigation of self-assembled monolayers of α-helical peptides and protein films (bovine serum albumin).
Main Results:
- Photoelectron spectral widths depend on substrate magnetization orientation and polarization.
- Helicity-dependent molecular ionization cross sections lead to spin-polarized holes.
- Substrate magnetization affects ionization energies and work function, enabling measurement of spin-dependent energy barriers.
Conclusions:
- Chiral organic films exhibit spin-dependent interactions with photoelectrons.
- The study quantifies spin-dependent energy barriers to electron transmission through chiral films.
- Findings offer insights into spin-polarized hole generation and potential applications in spintronics.
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