Broadband photoresponse and rectification of novel graphene oxide/n-Si heterojunctions

We report a novel graphene oxide (GO) based p-n heterojunction on n-Si. The fabricated vertical GO/n-Si heterojunction diode shows a very low leakage current density of 0.25 mu A/cm(2) and excellent rectification characteristics upto 1 MHz. The device on illumination shows a broadband (300-1100 nm) spectral response with a characteristic peak at similar to 700 nm, in agreement with the photoluminescence emission from GO. Very high photo-to-dark current ratio (>10(5)) is observed upon illumination of UV light. The transient photocurrent measurements indicate that the GO based heterojunction diodes can be useful for UV and broadband photodetectors, compatible with silicon device technology. (C) 2013 Optical Society of America