Electrical and interface state density properties of the 4H-nSiC/[6,6]-phenyl C61-butyric acid methyl ester/Au diode

The electrical and interface state density properties of the Ni/4H-nSiC/PCBM/Au diode have been investigated by current–voltage, capacitance–voltage and conductance–frequency methods. The ideality factor, barrier height and series resistance values of the diode were found to be 2.28, 1.10 eV and 3.76 × 104 Ω, respectively. The diode shows a non-ideal I–V behaviour with an ideality factor greater than unity that could be ascribed to the interfacial layer, interface states and series resistance. The obtained barrier height (1.10 eV) of the Ni/4H-nSiC/PCBM/Au diode is lower than that of Ni/4H-nSiC diode (1.32 eV). This indicates that the PCBM organic layer induces a change of 160 meV in the barrier height of the Ni/4H-nSiC diode. The interface state density of the diode was determined from Gp/ω–f plots and was of order of 5.61 × 1012 eV−1 cm−2.