1. Brazilian Nanotechnology National Laboratory (LNNano) Brazilian Center for Research in Energy and Materials (CNPEM) Campinas SP 13083‐100 Brazil
2. Instituto de Física Universidade Federal do Rio de Janeiro Rio de Janeiro RJ 21941‐972 Brazil
3. Instituto de Química Universidade Federal do Rio de Janeiro Rio de Janeiro RJ 21941‐909 Brazil
4. Institute of Chemistry University of Campinas Campinas SP 13083‐970 Brazil
5. Postgraduate Program in Materials Science and Technology São Paulo State University Bauru SP 17033‐360 Brazil
6. Center for Sensors and Devices Bruno Kessler Foundation (FBK) Trento 38123 Italy
7. Department of Applied Physics “Gleb Wataghin” Institute of Physics University of Campinas Campinas SP 13083‐859 Brazil
8. Mackenzie Presbyterian University São Paulo 01302‐907 Brazil