All solid-state electrochromic device consisting of a water soluble viologen dissolved in gelatin-based ionogel - Benedetti, Tânia Machado; Carvalho, Tânia; Iwakura, Daniel Campos; Braga, Filipe; Vieira, Bruna Ricciardi; Vidinha, Pedro; Gruber, Jonas; Torresi, Roberto Manuel (Solar Energy Materials and Solar Cells, 2015)