The Study Of Reactive Frequency Sputtering Prepared Electrochromic NiO_x Films

Electrochromic materials are characterised by a reversible and persistent change of optical property under the action of an applied electric field. It's outlook changes from bleached to colored state.or changes from one to another or more colors. This kind of materials have good open circuit memory, low energy consumption, compatibility with intergrated circuit, no look-out angle, large working temperature range, obtainable mid-state, low materials cost. They have a promising future in the application in large-area display, smart windows, glare-free mirror, photoelectric energy switcher and memory.Researchers have found many materials have electrochromic property, the most intensively studied are WO₃ and NiO_x. NiO_x is a classical p-type semiconductor, it colors anodically. It has large optical modulation range in visible region, high color efficiency, neutral gray color in it's colored state, can be composed a complementary electrochromic device with cathodically colored WO3, so it draws more and more attention in recent years.Researchers mainly used cathodically electrolytic deposition, anodically oxide deposition, electrochronic beam evaporation and sputtering methods to prepare NiO_x. In our own work we used reactive frequency sputtering methods prepared NiO_x under different oxygen partial pressure, then annealled films in different temperature in the air, finally we resorted to XRD, XPS, SEM, CV to studuy the property of films. In this work I focused on two points: oxygen partial pressure and annealing temperature. We also studied few about how the electrochemical reaction affect the films.