Fast electrochromic switching of electrospun Cu-doped NiO nanofibers

In this report, one-dimensional Cu-doped NiO nanofibers were synthesized by electrospinning and their electrochromic (EC) performance was investigated. It is demonstrated that the Ni(0.9)7Cu(0.03)O nanofibers exhibit particularly fast switching speed (1.6 s for coloring and 0.9 s for bleaching) among NiO-based EC devices reported so far. Furthermore, other outstanding EC properties, including large transmittance modulation (73% at 550 nm), high coloration efficiency (77.9 cm(2) C-1) and good cycling durability (80% after 2000 cycles), were also achieved for Ni0.97Cu0.03O nanofibers. These attractive EC properties are attributed to their one-dimensional nanostructures with small size grains and superior electrical conductivity. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.