A simple method for fabrication of graphene-silicon Schottky diode for photo-detection applications

In this work, we proposed a new method to fabricate a graphene/silicon Schottky diode using laser ablation of highly oriented pyrolytic graphite in liquid nitrogen to form few layers of graphene. This method, compared to other fabrication approaches for graphene-based devices is simpler, cost effective, efficient, and enjoys a higher degree of repeatability. The obtained I-V characteristics show that the device's ideality factor is about 7 for n-type and 17 for p-type substrates. A graphene/p-type Si Schottky diode with the Schottky barrier height of 0.45 eV at room temperature shows higher degree of sensitivity to light than an n-type one with the barrier height of 0.41 eV. It is shown that the measured current increases with the ambient temperature. An n-type substrate shows a better reproducibility in terms of the Schottky diode current.