The photoconductivity of dialkyl-2-phenylnaphthalene derivatives

Abstract

We have investigated charge carrier transport in the smectic mesophases of dialky 2-phenylnaphthalene derivatives. Some of the dialkyl derivatives exhibited highly ordered mesophases at ambient temperatures or lower. We could get non-dispersive transient photocurrents upon a pulse illumination from an excimer laser (wave length =308nm).
The carrier mobility of 8-PNP-4 in the smectic B phase was 6x10^-3cm²/Vs, and 3x10^-2cm²/Vs in the smectic E phase. These were three to four times larger than those in alkyl-alkoxy derivatives.
The carrier mobility depended on neither electric field nor temperature in a wide temperature range of -24 to 80^oC.