Determination of the deep-hole capture cross-section in a-Se via xerographic and interrupted-field time-of-flight techniques

Abstract

Combined techniques based on first-cycle xerographic residual potential, cycled-up saturated xerographic residual potential, and interrupted field time-offlight (IFTOF) measurements are used to determine the hole-drift-mobility-lifetime product μτ deep trapping time,τ, integrated deep-trap concentration, N _p trap capture coefficient and trap capture radius in a range of a-Se films. Very good agreement is observed between the μτ products determined via xerographic and IFTOF methods. Ballistic and diffusional deep-trapping models applied to this prototype amorphous semiconductor indicate that the capture radius is 2-3 [Abreve], indicative of neutral trapping centres with an integrated density of about 10¹³cm⁻³