Study of transport properties in fullerene-doped polysilane films using flash photolysis time-resolved microwave technique

The charge carrier photo generation in fullerene (C-60) doped polysilane (PS) is a multistage process including, photo induced electron transfer between polysilane to C-3(60)* and relaxation of the charge-transfer state which results in polaron pair (PS.+ and C-60(center dot-)) formation. To study the mobility of charge carriers in polysilane films (PS1-8) doped with fullerene (C-60), the flash photolysis time-resolved microwave conductivity (FP-TRMC) measurements have been performed. Second harmonic generation (SHG), laser of wavelength 532 nm has been used as excitation source. The highest phi Sigma mu value (7 x 10(-5) cm(2)/V s) obtained for PS6 among all polysilanes due to its highly ordered structure. The photo carrier generation efficiency of polysilane films have increased due to fullerene doping. The fast decay kinetics of TRMC signal is due to backward electron transfer between PS.+ and C-60(center dot-) where as slow decay can be attributed to charge recombination after diffusion process. (c) 2005 Elsevier B.V. All rights reserved.