Alternating‐Current Properties of Organic Semiconductor Solid Capacitor

Abstract

This paper deals with the a‐c properties of a new type of aluminum solid electrolytic capacitor in which organic semiconductors are employed as the counterelectrode. Both equivalent series capacitance and resistance (ESR) were measured between 90 Hz and 22 MHz frequencies and their temperature dependence was determined between −55° and +85°C. Excess series capacitance and ESR which were introduced by the use of the organic semiconductor counterelectrode were separated analytically, and the origin of the impedance connected in series of the anodic oxide is discussed. Very stable a‐c properties were observed in the high frequency and low temperature regions, which permitted explanation of the a‐c properties with simple models, such as a distributed circuit or dispersions owing to various interfaces. In the low frequency region, the capacitance and ESR increased with decreasing frequency and increasing temperature. It is suggested that the low frequency dissipation is dominated by the interfacial polarization due to polymer binder in contact with the anodic oxide.