LAUSR

In this article, we have demonstrated a solid carbon source such as camphor as a natural precursor to synthesize a large area mono/bi-layer graphene (MLG) sheet to fabricate nanowire junction based near infrared photodetectors (NIRPDs). In order to increase the surface-to-volume ratio, we have developed Si-nanowire arrays (SiNWAs) of varying lengths by etching planar Si. Then, the camphor based MLG/Si and MLG/SiNWAs schottky junction photodetectors have been fabricated to achieve efficient response with self-driven properties in the near infrared (NIR) regime. Due to a balance between light absorption capability and surface recombination centres, devices having SiNWAs obtained by etching for 30 min shows a better photoresponse, sensitivity and detectivity. Fabricated NIRPDs can also be functioned as self-driven device which are highly responsive and very stable at low optical power signals upto 2V with a fast rise and decay time of 34/13 ms. A tremendous enhancement has been witnessed from 36 µA/W to 22 mA/W in the responsivity at 0V for MLG/30 min SiNWAs than planar MLG/Si PDs indicating an important development of self-driven NIRPDs based on camphor based MLG for future optoelectronic devices.