Graphene, the two-dimensional monolayer of carbon, is an essential building block for advanced electronic applications. Graphene is often integrated with bulk conductors, metals, and semiconductors for optoelectronic applications. The semimetal bismuth, that shares many electronic properties with these other conductors, is interesting because like graphene, it is a gapless conductor of high electronic mobility with linear dispersion relations and low electronic density. We study the doping of graphene by $\mathrm{Bi}$ and the interfacial electric dipole. Graphene Raman spectroscopy results show that there is a very large charge transfer between graphene and bismuth. This doping is larger than in the interfaces of graphene with metals such as $\mathrm{Cu}$ and semiconductors such as $\mathrm{Si}$. Our findings are in good agreement with recent theoretical results for graphene bismuth interfaces. We also present a demonstration of zero-bias photocurrent generation that is enabled by the electric dipole at the graphene-bismuth interface.

• Received 3 May 2018
• Revised 2 August 2018

DOI:https://doi.org/10.1103/PhysRevApplied.10.044020