Evidence for formation of multi-quantum dots in hydrogenated graphene
1 Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK
2 Department of Physics, National Taiwan University, Taipei, 106, Taiwan
3 Graduate Institute of Applied Physics, National Taiwan University, Taipei, 106, Taiwan
4 Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan
Nanoscale Research Letters 2012, 7:459 doi:10.1186/1556-276X-7-459Published: 16 August 2012
We report the experimental evidence for the formation of multi-quantum dots in a hydrogenated single-layer graphene flake. The existence of multi-quantum dots is supported by the low-temperature measurements on a field effect transistor structure device. The resulting Coulomb blockade diamonds shown in the color scale plot together with the number of Coulomb peaks exhibit the characteristics of the so-called ‘stochastic Coulomb blockade’. A possible explanation for the formation of the multi-quantum dots, which is not observed in pristine graphene to date, was attributed to the impurities and defects unintentionally decorated on a single-layer graphene flake which was not treated with the thermal annealing process. Graphene multi-quantum dots developed around impurities and defect sites during the hydrogen plasma exposure process.