https://doi.org/10.1051/epjap/2014140272
Charge carrier trapping in highly-ordered lyotropic chromonic liquid crystal films based on ionic perylene diimide derivatives
1
Institute of Physics, National Academy of Sciences of Ukraine, Prospect Nauky 46, 03028
Kyiv, Ukraine
2
Center for Physical Sciences and Technology, Savanoriu 231, LT-02300
Vilnius, Lithuania
3
Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Murmanska 5, 02660
Kyiv, Ukraine
4
IMEC, Kapeldreef 75, B-3001
Leuven, Belgium
a e-mail: kadash@iop.kiev.ua
Received:
1
July
2014
Revised:
21
September
2014
Accepted:
26
September
2014
Published online:
25
November
2014
Charge carrier trapping in thin films of lyotropic chromonic liquid crystals (LCLCs) based on ionic perylene diimide derivative and in chemically-similar neutral N,N′-dipentyl-3,4,9,10-perylene-dicarboximide (PTCDI-C5) films is investigated by thermally-stimulated luminescence (TSL) technique. The LCLC films comprise elongated molecular aggregates featuring a long-range orientational order. The obtained results provide direct evidence for the improved energetic ordering (smaller effective energetic disorder) in aggregated LCLC films as compared to conventional PTCDI-C5 films. The width of the density-of-state distribution of 0.09 eV and 0.13 eV was estimated for the LCLC and PTCDI-C5 films, respectively. Relatively small effective energetic disorder in LCLC films is ascribed to formation of macroscopically larger LCLC aggregates.
© EDP Sciences, 2014
