1. CQM - Centro de Química da Madeira, MMRG, Universidade da Madeira, Campus da Penteada, 9020-105 Funchal, Portugal
2. Departamento de Física, IUdEA, Universidad de La Laguna, 38200 San Cristóbal de La Laguna, Tenerife, Spain
3. School of Materials Science and Engineering/Center for Nano Energy Materials, Northwestern Polytechnical University, 710072 Xi’an, China