Researchers in Florida have developed a doped form of graphene that makes graphene solar cells much more efficient. In an article in NanoLetters they report a power efficiency of 9 per cent, compared to 1.9 per cent for undoped graphene.
As we reported last month, the addition of quantum dots of lead sulphide to graphene makes the material absorb more of the light that falls of its surface.
Now, Researchers at the University of Florida have pulled a similar trick with an organic dopant, the catchily named: trifluoromethanesulphonyl-amide.
The team added a layer of doped graphene to a silicon substrate to create a graphene/silicon Schottky junction. The doped graphene increases the electric field across the junction between the semiconductor (silicon) and the metal (graphene). This means electrons and holes can be collected more efficiently, which in turn means more power can be generated.
Lead researcher Seffaatin Tongay told NanotechWeb: "The final device is robust, cheap and easy to make. What is more, transferring graphene onto silicon causes minimal disturbance at the graphene surface, so the interface remains pristine."
The researchers are now working on other coatings and playing with device structure in a bid to push the power efficiency even higher.