Synergistic enhancement of dual-color electrochromic performance in NiO/CdS quantum dots composite film

Abstract

NiO is an electrochromic material with extremely strong light modulation capability. However, the defects of the material, such as simple color change and poor cycle stability, limit its application in electrochromic devices and require further improvement and optimization. Nickel-based electrochromic films were firstly prepared by simple hydrothermal method and CdS quantum dots sensitization. The composite electrochromic films adsorbed CdS quantum dots show a multifunctional non-electrochromic film with multiple color changes. It shows up to 54.7% optical modulation range and reversible conversion of two colors. We believe that the electrochromic properties of the composite film are improved due to the synergistic effect of the combination of NiO and CdS in the composite film, which can improve the charge transfer dynamics and light modulation efficiency. Compared with NiO, CdS has a higher carrier density, which increases the charge storage capacity in the composite film, which can improve the color development efficiency and improve the electrochromic reaction. The existence of CdS in the composite film improves the structural stability of NiO. CdS acts as a buffer layer to reduce stress and prevent NiO degradation during repeated coloring and bleaching cycles, improving cycle stability and durability of electrochromic devices. This study provides a reference for the development of NiO polychromatic electrochromic materials and extends the range of non-electrochromic materials from metal oxides to sulfides.