Development and characterization of self-powered, highly sensitive optoelectronic device based on PVA-rGO nanofibers/n-Si

This study provided a promising way to fabricate low-cost and high-performance Poly (vinyl alcohol)-reduced graphene oxide (PVA-RGO) nanofibers/n-Si heterojunction photodetector. For this purpose, the hybrid heterojunction with a very-high rectification ratio (2.4 x 106) was achieved by successfully coating PVA-RGO nanofibers on n-Si wafer by electrospinning method. When the electro-optical analysis of the fabricated heterojunction photodetector under visible light depending on the light intensity, ultraviolet (UV) and infrared (IR) lights was examined in detail, it was observed that the photodetector exhibited both self-powered behavior and very high photo-response under each light sources. However, the highest optical performance was obtained under UV (365 nm) originated from PVA-RGO layer and IR (850 nm) light from both interfacial states between PVA-RGO nanofibers and Si and from Si layer. Under 365 nm UV light, the maximum performance values of R, D, ON/OFF ratio, normalized photo-dark-current ratio and external quantum efficiency (%) were obtained as 688 mA W-1, 1.15 x 1015Jones, 2.49 x 106, 8.28 x 1010 W-1 and 234%, respectively.