Role of nanowire length on the performance of a self-driven NIR photodetector based on mono/bi-layer graphene (camphor)/SinanowireSchottky junction

International audienceIn this article, we have demonstrated a solid carbon source such as camphor as a naturalprecursor to synthesize a large area mono/bi-layer graphene (MLG) sheet to fabricate a nanowirejunction-based near infrared photodetectors (NIRPDs). In order to increase the surface-tovolumeratio, we have developed Si-nanowire arrays (SiNWAs) of varying lengths by etchingplanar Si. Then, the camphor-based MLG/Si and MLG/SiNWAs Schottky junctionphotodetectors have been fabricated to achieve an efficient response with self-driven propertiesin the near infrared (NIR) regime. Due to a balance between light absorption capability andsurface recombination centers, devices having SiNWAs obtained by etching for 30 min shows abetter photoresponse, sensitivity and detectivity. Fabricated NIRPDs can also be functioned asself-driven devices which are highly responsive and very stable at low optical power signals upto 2 V with a fast rise and decay time of 34/13 ms. A tremendous enhancement has beenwitnessed from 36 μAW−1 to 22 mAW−1 in the responsivity at 0 V for MLG/30 min SiNWAsthan planar MLG/Si PDs indicating an important development of self-driven NIRPDs based oncamphor-based MLG for future optoelectronic devices