Electron transport characteristics in nanosegregated columnar phases of perylene tetracarboxylic bisimide derivatives bearing oligosiloxane chains

Abstract

Electron transport characteristics in nanosegregated columnar phases of perylene tetracarboxylic bisimide (PTCBI) derivatives bearing oligosiloxane chains are studied over wide temperature ranges using a time-of-flight (TOF) method. In the ordered columnar phases of the PTCBI derivatives bearing disiloxane chains, the electron mobilities exceed 0.1 cm² V⁻¹ s⁻¹ at room temperature. In the disordered columnar phase of the PTCBI derivative bearing trisiloxane chains, the electron mobility reaches the order of 10⁻³ cm² V⁻¹ s⁻¹ at around room temperature. These electron mobilities are temperature-independent at around room temperature. However, their dependence upon the electric field becomes larger when the temperature is lowered below room temperature; this behavior is described by a hopping transport mechanism. The experimental results are analyzed using a one-dimensional disorder model.