Nanocomposites and nanomaterials

Low-temperature thermoluminescence of film and nanocomposites of silicon organic polymer

N. Ostapenko1, O. Kerita1, 2, Yu. Ostapenko1, G. Telbiz3

1Institute of Physics of NASU, Nauka pr. 46, Kiev 03028, Ukraine
e-mail: nina.ostapenko@ gmail.com
2National technical university of Ukraine “I. Sikorsky Kyiv polytechnic institute”, 37 Prospect Peremogy, Kiev 03056, Ukraine
3Institute of Physical Chemistry NASU, Pr. Nauky 31, 03039, Kyiv, Ukraine

Thermostimulated luminescence provides important information about the presence and the energy distribution of traps for charge carriers in silicon organic polymers that are promising materials for the transport and luminescent layers in electro-optical devices.
In the present work we study low temperature thermoluminescence (5–120 K) of poly(di-n-hexylsilane) (PDHS) films, nanocomposites PDHS/MCM-41 and PDHS/SBA-15 (when the polymer is introduced into nanopores of silica МСМ-41 and SBA-15 with diameter of pores 2.8 and 10 nm) as well as solutions of polymer in tetrahydrofuran. 
It is established that maxima and FWHMs of the thermoluminescence curves of nanocomposites significantly depend on the pore diameter of the nanoporous silica. In the nanocomposite PDHS/MCM-41 with a minimum pore diameter (2.8 nm), the number and depth of the traps as well as dispersion of their energy are significantly reduced compared to their values in the polymer film. This result agrees with the data obtained in the investigation of polymer solutions in tetrahydrofuran with different concentrations from 10–3 to 10–5 mol/l. 
It was shown that using the thermoluminescence method it is possible to control the number of charge carrier traps in the polymer, as well as their energy distribution by changing the diameter of silica nanopores.