Trions as Fundamental Species in Chemically Doped Polymer Semiconductors
Abstract
ABSTRACT Doping is a cornerstone strategy for enhancing charge transport in semiconducting polymers, important for their application in, for example, semi‐transparent electrode materials, thermoelectric devices, and antistatic coatings. Both chemical and electrochemical doping have, for this purpose, been the focus of extensive research resulting in considerable progress. However, the interactions between neutral excitons and doping‐induced charges to form multi‐particle states are largely unexplored in soft organic semiconductors, and their signatures remain poorly understood. Here, we demonstrate that coupling between excitons and polarons in doped polymers can lead to bound states such as trions (i.e., quasiparticles of an electron and two holes delocalized across three chromophores for p ‐doping), or bound exciton‐hole pairs. Combining spectroscopic evidence with theoretical insights, we hypothesize that polymer architecture, dopant chemistry, and charge delocalization govern the formation and stability of these multi‐particle states. More broadly, our findings reveal that trions and bound exciton‐hole pairs—that is, three‐body entities—are a key species in organic semiconductors that could open new pathways toward optoelectronic functionalities beyond conventional doping, including enhanced charge transport and quantum‐coherent excitations.
Article Details
Authors (24)
Hongmo Li
School of Materials Science and Engineering Georgia Institute of Technology Atlanta Georgia USA
Henry J. Kantrow
School of Chemical and Biomolecular Engineering Georgia Institute of Technology Atlanta Georgia USA
David A. Valverde‐Chávez
School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta Georgia USA
Meghan McNeil
Département de Chimie Université de Montréal Montréal Québec Canada
Arianna Magni
Department of Materials Science and Engineering
Mohammad Balooch Qarai
Department of Chemistry Temple University Philadelphia Pennsylvania USA
Jude Kpare
School of Materials Science and Engineering Georgia Institute of Technology Atlanta Georgia USA
Jaden Cramlet
Department of Materials Science & Engineering Stanford University Stanford California USA
Qiao He
Félix Thouin
Institut Courtois & Département de Physique Université de Montréal Montréal Québec Canada
Zhihao Feng
Hebei Short Process Steelmaking Technology Innovation Center, School of Materials Science and Engineering, Hebei University of Science and Technology , Shijiazhuang 050018,
Yadong Zhang
Key Laboratory of Advanced Optoelectronic Functional Materials of Gansu Province, Key Laboratory for New Molecule Materials Design and Function of Gansu Universities, College of Chemical Engineering and Technology
Andrew Comstock
Department of Physics, North Carolina State University 1 , Raleigh, North Carolina 27695,
Stephen Barlow
Renewable and Sustainable Energy Institute (RASEI)
Jason Azoulay
School of Materials Science and Engineering Georgia Institute of Technology Atlanta Georgia USA
Seung Soon Jang
School of Materials Science and Engineering Georgia Institute of Technology Atlanta Georgia USA
Renaud Demadrille
IRIG‐SyMMES University of Grenoble Alpes CEA CNRS Grenoble‐INP Grenoble France
Martin Heeney
Division of Physical Sciences & Engineering, Chemistry Program
Seth Marder
School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta Georgia USA
Nicholas J. Hestand
Department of Natural and Applied Sciences Evangel University Springfield Missouri USA
Alberto Salleo
Frank C. Spano
Department of Chemistry, Temple University 1 , Philadelphia, Pennsylvania 19122,
Carlos Silva‐Acuña
Institut Courtois & Département de Physique Université de Montréal Montréal Québec Canada
Natalie Stingelin
School of Materials Science and Engineering