Enhanced Thermochromic Properties of Vanadium Dioxide (VO2)/Glass Heterostructure by Inserting a Zr-Based Thin Film Metallic Glasses (Cu50Zr50) Buffer Layer

Chaoyang Kang,Yuanjun Yang,Cong Zhang,Haitao Zong,Liwei Zhang,Yingxue Yao,Ming Li

doi:10.3390/app8101751

Abstract

Vanadium dioxide (VO2) with reversible metal–insulator transition (MIT) is one of the most promising energy-efficient materials. Especially for VO2-based smart windows, the visible transmittance and solar modulation ability are the most critical parameters. However, VO2 thin films that are directly deposited onto glass substrates are of poor crystallinity and MIT performance, limiting the practical applications of VO2/glass heterostructures. In this paper, a buffer layer of Cu50Zr50 was introduced to build a novel Zr-based thin film metallic glass (VO2/Cu50Zr50/glass) with multilayer structures for thermochromic applications. It is observed that the insertion of a Cu50Zr50 buffer layer with appropriate thickness results in a clear enhancement of crystalline quality and MIT performance in the VO2/Cu50Zr50/glass thin films, compared with the single-layer VO2/glass thin films. Moreover, the VO2/Cu50Zr50/glass bi-layer films exhibit better optical performance with enhanced solar modulation ability (ΔTsol = 14.3%) and a high visible transmittance (Tvis = 52.3%), which represents a good balance between ΔTsol and Tvis for smart window applications.

Highlights

In response to a large energy-consuming and environmentally deteriorating condition, developing energy-saving materials and sustainable energy has aroused wide attention
The peaks that were located at 27.80◦ are attributed to the VO2 (011) peak (JCPDS No 43-1051), which is the feature diffraction peak for M1-phase VO2 thin films [29]
All of the VO2 thin films are strongly oriented along the [011] direction, whether or not buffer layers were inserted on the glass substrate

Summary

Introduction

In response to a large energy-consuming and environmentally deteriorating condition, developing energy-saving materials and sustainable energy has aroused wide attention. Vanadium dioxide (VO2 ) thin film is a first-order phase-changed material with superfast reaction speed that is near the critical temperature, 340 K [1,2]. This phase transformation is called a metal–insulator transition (MIT), and involves significant changes in electrical and optical characteristics. Various techniques have been developed to form VO2 thin films, for instance, molecular beam epitaxy [7], pulsed laser deposition [8], magnetron sputtering [9], and chemical vapor deposition [10]. High-quality VO2 thin films with the single crystalline characteristics have Its phase switching behavior makes VO2 a hopeful candidate for a variety of applications, such as smart windows [3], sensor devices [4], ultrafast switches [5], Mott field effect transistors [4,6], etc.

Methods

Results

Conclusion