Nanocomposites and nanomaterials

Influence of the various conductive polymer matrices on the structural and optical properties of Alq3 layers
Sypniewska M.1, Szczesny R.2, Skowronski L.3, Gondek E.4, Pokladko-Kowar M.4, Derkowska-Zielinska B.1 
1 Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, Torun 87-100, Poland. 
E-mail: beata@fizyka.umk.pl
2 Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, Torun 87-100, Poland. 
3 Institute of Mathematics and Physics, UTP University of Science and Technology, S. Kaliskiego 7, 85-796, Bydgoszcz, Poland.
4 Institute of Physics, Cracow University of Technology, Podchorążych 1, 30-084 Kraków, Poland. 

In this work, we investigated the structural and optical properties of tris(8-hydroxyquinoline)aluminum (Alq3) layers dispersed in various conductive polymer matrices such as poly(9-vinylcarbazole) (PVK), polystyrene (PS) and poly(3-hexylthiophene-2,5-diyl) (P3HT). The properties of the Alq3:polymer thin films prepared by dip-coating or/and spin-coating method were analyzed using UV-Vis and IR spectroscopies, photoluminescence (PL), as well as AFM and SEM/EDX. 
Alq3 is one of the most important metalloorganic compound used in organic light-emitting diodes (OLEDs) as an electron-transport material and emitting layer. Alq3 is a green emitter with PL peak wavelength in the range of 500 nm. In Alq3, the light emission originates from the ligand’s electronic π – π* transition from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) [1, 2]. 

1. Mahakhode, J.G., Dhoble, S.J., Joshi,C.P., Moharil,S.V. Blue-shifted photoluminescence of Alq3 dispersed in PMMA// Bull. Mater. Sci.-2011.-34, N 7.-P. 1649-1651.
2. Derkowska-Zielinska, B. Enhancement of third order nonlinear optical susceptibility of Alq3 in polar aprotic solvents.// Opt. Lett.- 2017.-42.-P.  567-570.