1. Photophysics & Optoelectronics group, Zernike Institute of Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
2. Departamento de Materia Condensada y Criogenia. Instituto de Investigaciones en Materiales. Universidad Nacional Autónoma de México. Ciudad Universitaria, A.P. 70-360, Coyoacán, 04510, Mexico City, Mexico
3. Macromolecular Chemistry and New Polymeric Material, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
4. Dipartimento di Fisica, Università degli Studi di Cagliari, cittadella universitaria 09040, Monserrato, Cagliari, Italy