Electrochromic Properties of NiO_x Films Deposited by DC Magnetron Sputtering

Abstract

Nickel oxide (NiOx) films were deposited onto ITO-coated glass at room temperature by DC magnetron sputtering and the electrochromic properties were investigated. The effects of film thickness on structure, morphology, electrochemical and electrochromic properties of NiOx films were systematically studied. X-ray diffraction and scanning electron microscopy results indicate NiOx films have the polycrystalline structure and the crystallinity improves with the increase of thickness. In atomic force microscopy analysis, the surface roughness of NiOx films increases as the thickness increases and large roughness is obtained in the films of more than 300 nm. The electrochemical properties were measured by using conventional three-electrode configuration in 1 M LiClO4-PC electrolyte and all the samples show good cyclic stability. A transmittance modulation of 62% between colored and bleached state at 550 nm wavelength is obtained for 500 nm thick film and the high color efficiencies of more than 62 cm2C-1 are obtained in NiOx films. However, coloring and bleaching response times increase with the increase of thickness because of the larger depth of charge insertion/extraction. The results confirm that magnetron sputtering technology provides a feasibility for electrochromic devices with excellent electrochromic performance.

Effect of Substrate Temperature on the Optical and Electrical Properties of Nitrogen-Doped NiO Thin Films

“…The difference between the angles of the rhombohedral and the fcc NiO was very small, due to the broadening of the peaks, and no difference appeared in the XRD spectra. The diffraction peaks around 37.2 • and 41.2 • were assigned to NiO (111) and NiO (200), while the others are characteristic of the ITO layers [16]. Diffraction peaks of (220) at 62.9 • and (311) at 75.4 • were not visible, which indicated a preferred orientation of the NiO thin films.…”

Hollow Cathode Gas Flow Sputtering of Nickel Oxide Thin Films for Hole‐Transport Layer Application in Perovskite Solar Cells

“…The GFS NiO 1+δ thin films exhibited a cubic rock salt structure according to the JCPDS PDF # 47-1049. [65][66][67][68] GI-XRD detects diffraction from the crystallographic planes with increasing tilting angle to the surface when 2θ increases. One can therefore estimate if residual stresses exist in the film.…”

High performance NiOx nanoplatelet based films by a scrape-coating method for bifunctional electrochromic and energy storage devices

“…27 Therefore, magnetron sputtering is an effective method to realize stable and reliable electrochromic performance of NiO x films in Li + electrolytes. [28][29][30] For example, Qiu et al 31 prepared NiO x films by direct current magnetron sputtering which achieved up to 62% transmittance change in 1 M PC/LiClO 4 , but their colouring and bleaching times were as long as 17 and 9.8 s, respectively. Acua et al 32 adjusted the radio frequency power to vary the crystallinity and grain size of the NiO films, achieving 55% transmittance change in 1 M PC/LiClO 4 , but the colouring and bleaching times were still 4.1 and 9.9 s, respectively.…”