Space charge build-up and transport in thin dielectric films: a new approach based on electroluminescence detection

A new way is presented for deriving space charge dynamics and transport parameters in thin films sandwiched between two metallic electrodes. The measurement method uses the detection of the electroluminescence excited by square voltage pulses. In this conference, we report on hydrogenated amorphous carbon layers synthesised by gas phase polymerisation. The space charge build-up time is derived from the electroluminescence time lag when the structure is excited by a single square voltage pulse. The relaxation time of the space charge is investigated by using a double pulse excitation. An optical transit-time technique is proposed to determine the carrier mobility.