Nanocomposites and nanomaterials
Magnetic resonance study of fluorine- and titanium-implanted rr-P3HT films. 
Kislyuk V.V.1, Melnyk A.K.2, Trachevskyi V.V.3
1G.V. Kurdyumov Institute for Metal Physic of the NAS of Ukraine. Vernadsky blvd.,36, Kyiv- 03142, Ukraine 
2 Institute for Sorption and Problems of Endoecology of the NAS of Ukraine. Naumov str.,13, Kyiv- 03164, Ukraine
 E-mail: mak106@ukr.net
3 Technical centre, NAS of Ukraine. Pokrovska str.,13, Kyiv- 04070, Ukraine 
Conjugated polymer films, in particular rr-P3HT (regio-regular poly(3-hexylthiophene-2,5-diyl)) are prospective for the organic electronics due to their outstanding semiconducting and optoelectronic properties, in particular, the possibility to control the conductivity of such structures via doping. In our current research, the ion implantation technique is used as an approach compatible with flexible electronic requirements due to the temperature of the process and possibility to apply reduced energies of the ions. Understanding of degradation mechanisms in polymer : dopant on the microscopic level leads to the improving of their intrinsic stability.
Two types of ions - Ti+ and F+  were implanted into the film of rr-P3HT  on a glass substrate (film thickness – from 40 to 50 nanometers) of 0.2, 1, 10 and 40 keV energies with the values of the fluences of 1013, 1014, 1015 cm-2  subsequent annealing in Ar atmosphere in order to modify their conductivity and structure. EPR spectra of samples studied contain three lines with g-factors: 2.008, 2.003 and in 1.962–1.978 range. Lower–field line is associated with charged sulfur states similar to those generated by gamma irradiation. The line with g=2.003, which is present in all the spectra of the samples studied, is attributed to residuals of the polymer synthesis and/or humidity groups. High-field components are possibly caused by localized polaronic state, this line can be associated with fragments where polaron is generated at the presence of oxygen known to be a dopant in such a polymer.1H NMR spectra show the influence of the increased oxygen content represented by the O1s/C1s parameter, with the shift of NMR lines maximum downfield influenced by the paramagnetic centers. These spectra are the sensitive tool for direct detection of the molecular hydrogen released after intense collisions of the ions with 40 keV energy and 1014 cm-2, with the evidence of the formation of carbon-rich fragments which have high conductivity and can also contribute into the overall conductivity.