Current distribution effects in organic sexithiophene field effect transistors investigated by lock-in thermography: Mobility evaluation issues

In this Letter, a lock-in thermography technique has been used to investigate the actual current distribution profile in the active channel region of organic field effect transistors. The high accuracy of the setup shows an evidence of nonuniformity in the current flow over the device area. The physical origin of this experimental occurrence is tentatively ascribed to a not uniform contact resistance distribution along the channel width or to inhomogeneities in the interface traps distribution. The subsequent implications on the carrier mobility evaluation are discussed too.