Boron-doped graphene from boron-doped copper substrate for self-powered photodetector

Abstract

We investigate a method to prepare boron-doped graphene (BG) using a boron-doped copper film as both the substrate for graphene growth and the boron dopant source. About 1.6 at.% of boron was incorporated in the BG film. The BG had a bilayer structure, whereas the undoped pristine graphene (PrG) had a monolayer structure. The graphene films were transferred to the surface of n-type Si to fabricate PrG/n-Si and BG/n-Si diodes. The BG/n-Si diode had a slightly larger Schottky barrier height than the PrG/n-Si, indicating p-type doping in the BG film. Both the BG/n-Si and PrG/n-Si exhibited self-powered photodetection to 0.3 mW/cm2 of 365 nm UV light, and the ON/OFF ratio was 1.5 × 104 for the BG/Si diode and 2.9 × 103 for the PrG/Si diode. Compared with the PrG/n-Si diode, the BG/n-Si had a higher ON/OFF ratio due to its lower dark current and a higher barrier height.