Vacancy-defect assisted electrochromic applications in V2O5 nanomaterials
Bhalchandra K. Mandlekar, Amar L. Jadhav, Ashwini Pol, Anamika V. Kadam
Abstract
Vacancy defects can result in visible imperfections in the material’s lattice structure; however, they also enhance its effectiveness in various applications. In the present study, we have experimentally investigated how vacancy defects influence the electrochromic properties. This study presents a comparative analysis of the electrochromic (EC) properties of V₂O₅ thin films synthesized using ammonium metavanadate (NH 4 VO 2 ) and commercially available V 2 O 5 via a hydrothermal approach. Structural and morphological analyses were performed to confirm the formation of a microporous network and a nanosheet of V 2 O 5 nanomaterials. Furthermore, X-ray photoelectron spectroscopy (XPS) was employed to investigate oxygen vacancies in V 2 O 5 films. The cyclic voltammetry (CV) and in-situ optical variation results highlighted the positive impact of oxygen vacancies on the EC performance. The maximum coloration efficiency of multicolored V 2 O 5 -N thin films were 96.23 cm 2 C −1 at a 633 nm wavelength, with 500 color/bleach cycles in 0.5 M LiClO 4 + PC electrolytes. The microporous network and nanosheet morphology of V 2 O 5 thin films exhibited distinct optical hues with excellent long-term EC cycling stability. The high coloration efficiency (CE) and EC stability of V 2 O 5 thin films prepared using NH 4 VO 2 demonstrate the significant impact of oxygen defects.