Electronic properties, optical properties and diffusion behavior of WO3 with H+, Li+ and Na+ intercalated ions: A first-principles study

• Published in: Journal of solid state chemistry 2021-05, Vol.297, p.122082, Article 122082
• Main Authors: Cui, Yuanyuan, Wang, Qinfan, Yang, Guang, Gao, Yanfeng
• Format: Article
• Language: English
• Subjects: Diffusion behavior; Electrochromism; First-principles calculation; Tungsten trioxide
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2021.122082

Tungsten trioxide (WO3) is a representative electrochromic material that can change their optical properties under voltage pulse and has attracted great interest in the applications of energy-efficient windows. Models of M0.125WO3 (M ​= ​H+, Li+ and Na+) were built to simulate the optical properties and diffusion behaviors of the colored state of WO3 materials by first-principles calculations. The results indicate that the Li+ intercalated WO3 shows the highest modulation efficiency of the visible light region, while the Na+ intercalated WO3 possesses the highest modulation efficiency of the infrared light (IR) region among all three systems. Moreover, the study of the diffusion behaviors illustrates that the diffusion energy barriers decrease along with the reduction of intercalated ion sizes. Thus, the diffusion energy barriers of H+, Li+ and Na+ in WO3 can be arranged in the order of Na+ ​> ​Li+ ​> ​H+, which demonstrates that H+, Li+ and Na+ intercalated ion may affect the response time in electrochromic WO3 windows. Our first-principles calculations suggest that the diffusion direction of H+, Li+ and Na+ is c, a, b, respectively. In addition, the response time of three kinds of intercalated systems can be ranked as H+ ​