Surface modification of sputter deposited γ-WO3 thin film for scaled electrochromic behaviour

Abstract

In this research work, the synthesis and the electrochromic (EC) performance of the active material (γ-WO3) is reported. Nanoporous γ-WO3 thin film was grown directly on the indium tin oxide (ITO) coated glass substrate using DC magnetron sputtering in a reactive environment (Ar:O2 = 2:1) at room temperature (RT). To achieve the nanoporous-nanocrystalline behaviour of the active material, a thermal treatment (250 °C) was given, which modified the compact film surface into nanospheres. This surface modification is responsible to alter the physical, optical and electrochromic properties of the active material. The physical properties of the active material were probed in detail using X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and energy-dispersive X-ray analysis (EDX). The optical and electrochromic behaviour of the active electrode material was analyzed using UV–Vis spectroscopy and cyclic voltammetry (CV). It has been found that the modified electrode exhibited large optical modulation (46%), high reversible redox behaviour (higher current density) and good cyclic stability at least upto 500 cycles, causes scaled EC behaviour. This electrochemically active architecture allow one to fabricate the device for energy harvesting applications. Our work indorse human comfort with financial benefits and may play a crucial role in “green nanotechnology”