Space-charge limited conduction in doped polypyrrole devices

作者：Anjaneyulu P^*; Sangeeth C S Suchand; Menon Reghu

来源：Journal of Applied Physics, 2010, 107(9): 093716.

DOI：10.1063/1.3373393

Doping dependent current-voltage (I-V) and capacitance-voltage (C-V) measurements were carried out on polypyrrole devices in metal-polymer-metal sandwich structure. Temperature dependent I-V measurements infer that space-charge limited conduction (SCLC) with exponential trap distribution is appropriate for the moderately doped samples, whereas trap-free SCLC is observed in lightly doped samples. Trap densities and energies are estimated, the effective mobility is calculated using the Poole-Frenkel model, and the mobility exhibits thermally activated behavior. Frequency dependent capacitance-voltage characteristics show a peak near zero bias voltage, which implies that these devices are symmetric with a negligible barrier height at the metal-polymer interface. Low frequency capacitance measurements have revealed a negative capacitance at higher voltages due to the processes associated with the injection and redistribution of space-charges.

• 出版日期2010-5-1