Role of nanowire length on the performance of a self-driven NIR photodetector based on mono/bi-layer graphene (camphor)/Sinanowire Schottky junction
Résumé
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 a nanowire
junction-based near infrared photodetectors (NIRPDs). In order to increase the surface-tovolume
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 an efficient response with self-driven properties
in the near infrared (NIR) regime. Due to a balance between light absorption capability and
surface recombination centers, 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 devices which are highly responsive and very stable at low optical power signals up
to 2 V with a fast rise and decay time of 34/13 ms. A tremendous enhancement has been
witnessed from 36 μAW−1 to 22 mAW−1 in the responsivity at 0 V 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.