Electrical characterization of Al/fluorescein sodium salt organic semiconductor/Au diode by current-voltage and capacitance-voltage methods

Abstract

The organic Schottky diode of fluorescein sodium salt using aluminium and gold metals were fabricated. Electronic and interface state properties of the Al/p-FSS Schottky diode were investigated by current-voltage and capacitance-voltage methods. The electronic parameters such as barrier height (φ_β =0.72 eV), ideality factor (n=3.05) and series resistance (7.73 kΩ) of the Schottky diode were determined by performing different plots. The φ_β (C-V) value obtained capacitance-voltage measurements is 1.05 eV . The barrier height obtained from the C-V measurements is higher than that of obtained from the I-V measurements. The difference between φ_β (I-V) and φ_β (C-V) barrier height values can be due to interfacial layer, excess capacitance and barrier inhomogenity. The shape of the density distribution of the interface states is in the range of E_SS-0.02 eV to E_SS-1.21 eV.