Highly Substituted 10-RO-(hetero)acenes—Electric Properties of Vacuum-Deposited Molecular Films
Bernard Marciniak,
Sylwester Kania,
Piotr Bałczewski,
Ewa Różycka-Sokołowska,
Joanna Wilk,
Marek Koprowski,
Jacek Stańdo,
Janusz Kuliński
Affiliations
Bernard Marciniak
Structural & Material Chemistry Group, Faculty of Science and Technology, Institute of Chemistry, Jan Dlugosz University in Częstochowa, Armii Krajowej 13/15, 42-200 Częstochowa, Poland
Sylwester Kania
Centre of Mathematics and Physics, Łódź University of Technology, Żeromskiego 116, 90-924 Łódź, Poland
Piotr Bałczewski
Structural & Material Chemistry Group, Faculty of Science and Technology, Institute of Chemistry, Jan Dlugosz University in Częstochowa, Armii Krajowej 13/15, 42-200 Częstochowa, Poland
Ewa Różycka-Sokołowska
Structural & Material Chemistry Group, Faculty of Science and Technology, Institute of Chemistry, Jan Dlugosz University in Częstochowa, Armii Krajowej 13/15, 42-200 Częstochowa, Poland
Joanna Wilk
Functional Materials Synthesis Group, Division of Organic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Łódź, Poland
Marek Koprowski
Functional Materials Synthesis Group, Division of Organic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Łódź, Poland
Jacek Stańdo
Faculty of Technical Physics, Information Technology and Applied Mathematics, Żeromskiego 116, 90-924 Łódź, Poland
Janusz Kuliński
Centre of Mathematics and Physics, Łódź University of Technology, Żeromskiego 116, 90-924 Łódź, Poland
The functionalization of the aromatic backbone allows the improvement of the electrical properties of acene molecules in the amorphous layered structures of organic thin films. In the present work, we discuss the electric properties of the stable, amorphous, vacuum-deposited films prepared from five highly substituted 10-RO-acenes of various electronic properties, i.e., two extreme electron-donor (1,3-dioxa-cyclopenta[b]) anthracenes with all RO substituents, two anthracene carbaldehydes and one benzo[b]carbazole carbaldehyde possessing both electron-donor and acceptor substituents. The hole mobility data were obtained using subsequent steady state space charge limited currents (SCLC) and Time of Flight (TOF) measurements, performed on the same sample and these were then compared with the results of theoretical hole mobility calculations obtained using the Density Functional Theory (DFT) quantum—chemical calculations using the Marcus–Hush theory. The study shows a good agreement between the theoretical and experimental values which allows for the quick and quantitative estimation of Einstein’s mobility values for highly substituted 10-RO anthracene and benzo[b]carbazole based on chemical calculations. This agreement also proves that the transport of holes follows the hopping mechanism. The theoretical calculations indicate that the reorganization energy plays a decisive role in the transport of holes in the amorphous layers of highly substituted hetero(acenes).
