Fabrication and electrical characterizations of graphene nanocomposite thin film based heterojunction diode

Abstract

The use of graphene in electronic devices is becoming attractive due to its inherent scalability and is thus well suited for flexible electronic devices. Here we present the electrical characterization of heterojunction diode, based on the nanocomposite of graphene (G) with silver nanoparticles (Ag NPs), at room temperature. The diode was fabricated by depositing nanocomposite on the n-Si substrate. The current – voltage (I – V) characteristic of the fabricated junction shows rectifying behavior similar to a Schottky junction. The junction parameters such as ideality factor (n), series resistance (Rs), and barrier height (ϕb) has been extracted, using various methods, from the experimentally obtained I – V data. The measured values of n, Rs and ϕb are 3.86, 45Ω and 0.367eV, respectively, as calculated from the I – V curve. The numerical values of these parameters calculated by different methods are in good agreement with each other showing the consistency of the applied calculating techniques. The conduction mechanism of the fabricated diode seems to have been dominated by the Trap Charge Limited Conduction (TCLC) behavior. The energy distribution of interface states density determined from forward bias I – V characteristic shows an exponential decrease with bias from 27 × 1013cm−2eV−1 at (Ec – 0.345)eV to 3 × 1013cm−2eV−1at (Ec – 0.398)eV.