HOLE TRANSPORT IN POLYSILANE FILMS UNDER ELONGATION

Negative field dependence of hole mobility was observed in poly(methyl phenylsilane) (PMPS) films doped with a plasticizer, dioctyladipate (D OA). By analyzing the hole mobilities in the framework of Bassler's di sorder formalism, the negative field dependence was found to be due to the large increase in the parameter Sigma, the positional disorder of hopping site distance. Furthermore, we succeeded in measuring the hol e mobility of DOA-doped PMPS film under elongation. In UV absorption a nd fluorescence spectrum measurements of the elongated film, a red shi ft of the absorption edge was observed only for the polarized light pa rallel to the elongation axis, and a new emission appeared at the long er wavelength, suggesting that the molecular orientation and the exten sion of sigma-conjugation length occurred with film elongation. The ef fect of film elongation was well reflected in the parameters in the ch arge transport expression for amorphous materials based on Bassler's d isorder formalism.