Capacitance of Organic Schottky Diodes Based on Copper Phthalocyanine (CuPc)

Abstract

The capacitance of an organic Schottky diode based on copper phthalocyanine (CuPc) is investigated. Based on the organic small-signal equivalent model established, we calculate the reverse capacitance CMetal of the organic Schottky diode with different kinds of metal cathodes (Mg, Al, Au). It is found that the reverse capacitance of the organic Schottky diode shows behavior as CMg > CAl > CAu at the same frequency, and according to our analysis, the reverse Schottky junction capacitance Cj is expected to have little effect on the reverse capacitance of the organic Schottky diode, and the space-charge limited current capacitance CS is considered to dominate the reverse capacitance, which limits the improvement of frequency characteristics of organic Schottky diodes.