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 µA/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 ~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.