Graphene's excellent conductivity is being utilized in numerous applications. In a recent experimental study, graphene's role in photoelectrochemical applications is invoked. The efficient separation of photo-generated electron hole pairs at iron oxide/graphene heterojunctions resulted in an improved water splitting efficiency.

http://pubs.acs.org/doi/abs/10.1021/nl303961c

light induced doping in CVD graphene

A recent work by Rice University scientists has revealed that graphene can be doped optically. This has been achieved by exploiting plasmon resonance of metal nanoparticle, arranged in a well ordered manner at nanoscale, deposited on single layer graphene. 
The study opens up doors for plasmonic and optoelectronic applications of graphene.


http://pubs.acs.org/doi/abs/10.1021/nn304028b