Electrochromic switching of evaporated thin films of bulky, electronic deficient metallo-phthalocyanines
Document Type
Article
Publication Date
5-5-2011
Abstract
Thin films of four-coordinated perfluoroalkyl-substituted phthalocyanines were prepared by physical vapor deposition. The electrochemical redox characteristics and simultaneous changes in the optical absorbance spectra of the films (40-215 nm) in contact with an aqueous LiCl electrolyte for charge compensation were compared to results obtained for the molecules dissolved in an organic solvent. A positive shift of the potential of the first ring-centered reduction relative to the unsubstituted or perfluorinated phthalocyanines was confirmed for solutions and clearly established for thin films. Following a conditioning of the films during the first reduction, chemically reversible and thermodynamically quasi-reversible reduction and reoxidation reactions were observed. A clear correlation of the injected charge with the appearance of isosbestic points characterized the reaction as a one-electron reduction. Diffusion limitation by charge-balancing lithium counterions could be detected only for thicker films leading to high switching speeds of the electrochromic reaction in thinner films of about a second and thus rendering the materials interesting candidates for organic electrochromic display applications. © 2011 American Chemical Society.
Identifier
79955559071 (Scopus)
Publication Title
Journal of Physical Chemistry C
External Full Text Location
https://doi.org/10.1021/jp2010748
e-ISSN
19327455
ISSN
19327447
First Page
8759
Last Page
8767
Issue
17
Volume
115
Recommended Citation
Nagel, Stefanie; Lener, Martin; Keil, Christopher; Gerdes, Robert; Łapok, Łukasz; Gorun, Sergiu M.; and Schlettwein, Derck, "Electrochromic switching of evaporated thin films of bulky, electronic deficient metallo-phthalocyanines" (2011). Faculty Publications. 11360.
https://digitalcommons.njit.edu/fac_pubs/11360