Capacitance of organic schottky diodes based on copper phthalocyanine (CuPc)

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 C_Metal 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 C_Mg > C_Al > C_Au at the same frequency, and according to our analysis, the reverse Schottky junction capacitance C_j is expected to have little effect on the reverse capacitance of the organic Schottky diode, and the space-charge limited current capacitance C_S is considered to dominate the reverse capacitance, which limits the improvement of frequency characteristics of organic Schottky diodes.