Repository logo
 

Temperature dependence of charge localization in high-mobility, solution-crystallized small molecule semiconductors studied by charge modulation spectroscopy

Accepted version
Peer-reviewed

Repository DOI


Type

Article

Change log

Authors

Meneau, AYB 
Olivier, Y 
Backlund, T 
James, M 
Breiby, DW 

Abstract

jats:pIn solution‐processable small molecule semiconductors, the extent of charge carrier wavefunction localization induced by dynamic disorder can be probed spectroscopically as a function of temperature using charge modulation spectroscopy (CMS). Here, it is shown based on combined field‐effect transistor and CMS measurements as a function of temperature that in certain molecular semiconductors, such as solution‐processible pentacene, charge carriers become trapped at low temperatures in environments in which the charges become highly localized on individual molecules, while in some other molecules the charge carrier wavefunction can retain a degree of delocalization similar to what is present at room temperature. The experimental approach sheds new insight into the nature of shallow charge traps in these materials and allows identifying molecular systems in which intrinsic transport properties could, in principle, be observed at low temperatures if other transport bottlenecks associated with grain boundaries or contacts could be removed.</jats:p>

Description

Keywords

Molecular semiconductors, Charge transport, Charge trapping, Charge Modulation Spectroscopy

Journal Title

Advanced Functional Materials

Conference Name

Journal ISSN

1616-301X
1616-3028

Volume Title

26

Publisher

Wiley
Sponsorship
We acknowledge material supply and financial support from Merck Chemicals Ltd through an industrial EPSRC CASE studentship. In addition, the work in Mons was supported by the Programme d’Excellence de la Région Wallonne (OPTI2MAT project) and FNRS-FRFC. D.W.B. acknowledges financial support from the Norwegian Research Council.