Electronic transport properties of Ir-decorated graphene.
Graphene decorated with 5d transitional metal atoms is predicted to exhibit many intriguing properties; for example iridium adatoms are proposed to induce a substantial topological gap in graphene. We extensively investigated the conductivity of single-layer graphene decorated with iridium deposited in ultra-high vacuum at low temperature (7 K) as a function of Ir concentration, carrier density, temperature, and annealing conditions. Our results are consistent with the formation of Ir clusters of ~100 atoms at low temperature, with each cluster donating a single electronic charge to graphene. Annealing graphene increases the cluster size, reducing the doping and increasing the mobility. We do not observe any sign of an energy gap induced by spin-orbit coupling, possibly due to the clustering of Ir.
Department of Physics, University of Maryland, College Park, MD 20742, USA.|Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742, USA.|Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
Yilin
Y
Wang
Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742, USA.
Shudong
S
Xiao
Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742, USA.
Xinghan
X
Cai
Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742, USA.
Wenzhong
W
Bao
Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
Janice
J
Reutt-Robey
Department of Physics, University of Maryland, College Park, MD 20742, USA.|Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742, USA.|School of Physics, Monash University, Victoria 3800, Australia.
Michael S
MS
Fuhrer