Abstract
Shallow traps for p-type charge carriers were found in a ladder-type poly(p-phenylene). Using the thermally stimulated current technique a trap depth of 0.1 eV was determined. The electrical current of a gold-ladder-polymer-gold structure at field strengths of 4*104 V cm-1 is space-charge limited. We propose a Gaussian trap distribution centred at 0.1 eV above the valence band edge.