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Superweak Coordinating Anion as Superstrong Enhancer of Cyanine Organic Semiconductor Properties
Author(s) -
Gesevičius Donatas,
Neels Antonia,
Yakunin Sergii,
Hack Erwin,
Kovalenko Maksym V.,
Nüesch Frank,
Heier Jakob
Publication year - 2018
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201800863
Subject(s) - cyanine , chromophore , organic semiconductor , photochemistry , ion , chemistry , fluorescence , aluminate , semiconductor , materials science , organic chemistry , optoelectronics , physics , quantum mechanics , cement , metallurgy
The superweak tetrakis(nonafluoro‐ tert ‐butoxy)aluminate coordinating anion was employed to introduce pseudo‐gas‐phase conditions to the 2‐[5‐(1,3‐dihydro‐1,3,3‐trimethyl‐2H‐indol‐2‐ylidene)‐1,3‐pentadien‐1‐yl]‐1,3,3‐trimethyl‐3H‐indolium chromophore. The resulting formation of a photoactive organic–inorganic hybrid salt has led to a highly stabilized excited state of the organic chromophore mainly due to the minimized lattice energy and Coulomb interactions. These highly beneficial features caused by the well dispersed negative charge of the anion have led to an enhanced neat spin‐casted film fluorescence intensity, prolonged fluorescence lifetime, smooth thin film surfaces and a record power photovoltaic efficiency of 3.8 % when compared to organic salts of this particular chromophore containing anions with localised negative charge. Clear evidence is given that a superweak coordinating anion is an emerging key parameter in cyanine dye photochemistry. This approach can be seen as a general guideline to prepare highly efficient ionic dyes for organic semiconductor applications.