Current distribution effects in organic sexithiophene FETs 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 FETs (oFETs). The high accuracy of the setup, for the first time, shows an evidence of not uniformity 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. The subsequent implications on the carrier mobility evaluation are discussed too.