Abstract
The hole drift mobility of poly(n-propylmethylsilane) showing thermochromism has been measured over a wide temperature range encompassing its glass transition temperature T g and its melting point T m. The drift mobility obeys Gill's empirical expression for the field and temperature dependences below T g. It levels off near 10-4cm2V-1s-1 with the disappearance of the field dependency above T g, and gradually decreased just below T m, where distinct thermochromism due to the change of the effective o conjugation length in the Si backbone chain was observed. Above T m the mobility increases again in the molten state. The lowering of the drift mobility due to the shortening of the o conjugation length was also observed in rapidly quenched samples which exhibited a mobility about one order of magnitude lower, strongly indicating that the effective o conjugation length in the Si backbone chain determines the charge-carrier transport properties in organopolysilanes.