1. School of Mechanical Engineering, University of Campinas,Laboratory of Photonic Materials and Devices,SP,Brazil
2. University of Trieste,Carbon Nanotechnology Group, Department of Chemical and Pharmaceutical Sciences,Italy
3. Polytechnic School, University of São Paulo (LME/EPUSP),Laboratory of Microelectronics,SP,Brazil
4. Institute of Physics, University of São Paulo,SP,Brazil