Improvement of electrochromic properties of NiO film doped with ZnO prepared by magnetron sputtering

Nickel oxide, as an anode electrochromic material, has the advantages of a large color modulation range, good cycle life and strong ion storage capacity, and low raw material price, so it is considered to have the potential for large-scale commercial application. In this paper, the electrochromic properties of the ZnO-doped NiO film prepared via magnetron sputtering technology were studied. Moreover, the content of ZnO in NiO films can be controlled by the adjustable ZnO target’s sputtering power. The doping of ZnO augmented the film crystallinity and the contact area between the film and the electrolyte, thereby improving electrochromic properties. Compared with pure NiO film, the NiO film doped with ZnO at a power of 40 W (the abbreviation is ZnO-40) markedly promotes the migration of Li + , the film’s cycle stability, and electrochromic properties. At the 20th cycle, the optical contrast of the ZnO-40 film was 45.27%, the coloration efficiency was 32.53 cm 2 /C, the coloration time was 3.1 s, and the bleaching time was 1.1 s. At the 100th cycle, the optical contrast was 43.66%, the coloration efficiency was 28.79 cm 2 /C, and the reversibility was 99.59%. After 1000 cycles, the optical contrast could steadily reach 42.83%, the coloration efficiency was 60.38cm 2 /C, and the reversibility was 98.12%.