The effect of the time-dependent on the capacitance-voltage frequency characteristics of polymer/inorganic semiconductor structure

Full text: A metallic poly-pyrrole film has been directly formed on a p-type Si substrate by means of an anodization method under conditions of constant current density by an electrolyte being held at a constant temperature of 55 deg. C that was composed of 0.40 M pyrrole and 0.10 M tetrabutylammonium tetrafluoroborate. An aluminum electrode was used as an ohmic contact. The poly-pyrrole/p-Si/Al structure has demonstrated clearly rectifying behavior by the current-voltage curves studied at room temperature. The capacitance-voltage-frequency curves of the structure have been measured at different frequencies at room temperature in dark. In order to observe the effect of the ageing, the measurements were also repeated 7, 15, 30, 60 and 90 days after fabrication of the poly-pyrrole /p-Si/Al structure. Interface states distribution curves obtained from the capacitance-frequency characteristics with respect to increasing ageing time. During the whole measurement process, the probe of holder on sample was fixed to eliminate effects of surface inhomogeneity