Dependence of charge carrier mobility of 4,4′,4″-tris(N-3-methylphenyl-N-phenylamino)triphenylamine on doping concentration of tetrafluoro-tetracyano-quinodimethane

Electrical transport of pure and tetrafluoro-tetracyano-quinodimethane doped 4,4′,4″-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) films have been studied at various temperatures and doping concentrations. Pure films show space charge limited conduction with field and temperature dependent mobility. The J–V characteristics of doped m-MTDATA were ohmic at low voltages due to thermally released carriers from dopant states. At higher voltages the current density increases nonlinearly due to field dependent mobility and carrier concentration thereby filling of tail states of HOMO of the host. The conductivity of doped films were analysed using the Unified Gaussian Disorder Model (UGDM). The carrier concentration obtained from the fitting show a non-linear dependence on doping concentration which may be due to a combined effect of thermally activated carrier generation and increased carrier mobility.

Transport properties of pure and tetrafluoro-tetracyano-quinodimethane doped 4,4′,4″-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) films have been studied at various temperatures and doping concentrations. Pure films show space charge limited conduction with field and temperature dependent mobility and doped films of m-MTDATA show ohmic behavior at low voltages due to thermally released carriers from dopant states. At higher voltages the current density increases non-linearly due to field dependent mobility and carrier concentration thereby filling of tail states of HOMO of the host. The conductivity of doped films were analysed using the Unified Gaussian Disorder Model (UGDM).Figure optionsDownload as PowerPoint slideHighlights
► ITO/m-MTDATA interface modification with F4-TCNQ provides ohmic contact.
► Pure m-MTDATA samples show SCLC with field and temperature dependent mobility.
► p-Doped m-MTDATA films show thermally activated carrier generation at low field.
► At high field these films show field dependent mobility and carrier concentration.
► The hole conductivity has increased nonlinearly with doping concentration.