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.