1. Department of Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
2. Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
3. NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
4. Instituto de Física, Universidade Federal de Mato Grosso, 78060-900 Cuiabá, Mato Grosso, Brazil
5. Departamento de Física, Universidade Federal do Ceará, 60455-760 Fortaleza, Ceará, Brazil