Charge transport in chlorine doped amorphous Se:Te xerographic photoreceptor films

Time-of-flight drift mobility experiments were carried out on a-Se_1?xTe_x (x = 0-0.1) with chlorine as an additive up to 70 atomic parts per million to investigate the charge transport mechanism in these xerographically important photoreceptor films. Hole drift mobility-temperature data indicate that hole transport in a-Se:Te alloys is controlled by a relatively discrete set of Te-introduced shallow traps (probably Te₁^? centres) at ～ 0.43 eV above E_v whose concentration increases nearly linearly with Te addition. Chlorine doping generates an additional set of traps (probably Cl₀^? centres) around the same energy as Te-induced traps in a similar fashion to the effect of Cl addition to a-Se. Electron drift mobility-temperature data for a-Se:Te alloys containing no Cl can also be interpreted by assuming Te-introduced electron traps at ～ 0.49 below E_c. There was no electron transport observable in Cl-doped a-Se:Te alloys.