Boron doping effects in electrochromic properties of NiO films prepared by sol–gel

In this paper, NiO films doped with B2O3 were first prepared by sol–gel. The effects of boron content on the structure and electrochromic properties of NiO films were studied with X-ray diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetric (CV) and UV–vis spectrophotometer, respectively. In addition, the roughness and phase of the bleached/colored were studied by atom force microscopy (AFM). B-doped prevent the crystallization of the films. The colored state transmittance could be significantly lowered when the boron added. The NiO film doped with boron exhibited a noticeable electrochromism with a variation of transmittance up to ∼60% at the wavelength range of 300–500 nm.