Symmetry based molecular design for triplet excitation and optical spin injection
File(s)
Accepted version
Author(s)
Szumska, Anna A
Sirringhaus, Henning
Nelson, Jenny
Type
Journal Article
Abstract
Spintronics, as a relatively new scientific field, is developing rapidly together with our understanding of spin related phenomena and spin manipulation. One of the challenges in the field is spin injection, which has been achieved optically in inorganic crystalline semiconductors, but not yet in organic semiconductors. Here, we introduce an approach whereby we apply group theory and computational methods to design molecular materials in which spin can be injected optically via circularly polarized light (CPL). Our approach is based on the use of group theory and double group theory to identify families of molecules whose symmetry satisfies design rules for optical excitation of triplets of particular properties. Employing such screening prior to detailed calculation can accelerate design by first identifying any structures that fail some criterion on grounds of symmetry. Here, we show using group theory and computational methods that particular families of molecules possess a low lying triplet state that can be excited with circularly polarized light causing spin polarization of an excited electron. Such structures are of potential interest for organic or molecular spintronics. We present an efficient procedure to identify candidate point groups and determine the excited state symmetry using group theory, before full calculation of excited states using relativistic quantum chemistry.
Date Issued
2019-09-21
Date Acceptance
2019-08-02
Citation
Physical Chemistry Chemical Physics, 2019, 21 (35), pp.19521-19528
ISSN
1463-9076
Publisher
Royal Society of Chemistry
Start Page
19521
End Page
19528
Journal / Book Title
Physical Chemistry Chemical Physics
Volume
21
Issue
35
Copyright Statement
This journal is ©the Owner Societies 2019. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Physical Chemistry Chemical Physics, after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.rsc.org/en/content/articlelanding/2019/CP/C9CP03384J
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/31463496
Grant Number
EP/P005543/1
Subjects
Science & Technology
Physical Sciences
Chemistry, Physical
Physics, Atomic, Molecular & Chemical
Chemistry
Physics
02 Physical Sciences
03 Chemical Sciences
09 Engineering
Chemical Physics
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2019-08-02