Spin Selectivity in Photoinduced Charge-Transfer Mediated by Chiral Molecules

John M Abendroth; Dominik M Stemer; Brian P Bloom; Partha Roy; Ron Naaman; David H Waldeck; Paul S Weiss; Prakash Chandra Mondal

doi:10.1021/acsnano.9b01876

Spin Selectivity in Photoinduced Charge-Transfer Mediated by Chiral Molecules

ACS Nano. 2019 May 28;13(5):4928-4946. doi: 10.1021/acsnano.9b01876. Epub 2019 May 7.

Authors

John M Abendroth^{1

2}, Dominik M Stemer^{1

3}, Brian P Bloom⁴, Partha Roy⁵, Ron Naaman⁶, David H Waldeck⁴, Paul S Weiss^{1

2

3}, Prakash Chandra Mondal⁷

Affiliations

¹ California NanoSystems Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States.
² Department of Chemistry and Biochemistry , University of California, Los Angeles , Los Angeles , California 90095 , United States.
³ Department of Materials Science and Engineering , University of California, Los Angeles , Los Angeles , California 90095 , United States.
⁴ Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States.
⁵ Department of Chemistry , Central University of Rajasthan , Kishangarh 305817 Ajmer , India.
⁶ Department of Chemical and Biological Physics , Weizmann Institute of Science , Rehovot 76100 , Israel.
⁷ Department of Chemistry , Indian Institute of Technology , Kanpur 208016 , India.

PMID: 31016968
DOI: 10.1021/acsnano.9b01876

Abstract

Optical control and readout of electron spin and spin currents in thin films and nanostructures have remained attractive yet challenging goals for emerging technologies designed for applications in information processing and storage. Recent advances in room-temperature spin polarization using nanometric chiral molecular assemblies suggest that chemically modified surfaces or interfaces can be used for optical spin conversion by exploiting photoinduced charge separation and injection from well-coupled organic chromophores or quantum dots. Using light to drive photoexcited charge-transfer processes mediated by molecules with central or helical chirality enables indirect measurements of spin polarization attributed to the chiral-induced spin selectivity effect and of the efficiency of spin-dependent electron transfer relative to competitive relaxation pathways. Herein, we highlight recent approaches used to detect and to analyze spin selectivity in photoinduced charge transfer including spin-transfer torque for local magnetization, nanoscale charge separation and polarization, and soft ferromagnetic substrate magnetization- and chirality-dependent photoluminescence. Building on these methods through systematic investigation of molecular and environmental parameters that influence spin filtering should elucidate means to manipulate electron spins and photoexcited states for room-temperature optoelectronic and photospintronic applications.

Keywords: chiral-induced spin selectivity; fluorescence quenching; molecular spintronics; optoelectronics; photoluminescence; photospintronics; spin filter.