Predictions of electronic structures and optical performance of potential near infrared absorber Sn0.33WO3

Changqing Liu,Lihua Xiao,Yi Yuan,Ping Peng,Wei Qiu,Qunwei Shu,Jingyun Qin

doi:10.1063/1.5127301

Abstract

For better synthesis and development of novel WO3-based near infrared absorbing materials for smart-window applications, the structural, electronic, and optical properties of hexagonal Sn0.33WO3 were investigated through the first-principles calculation. The optimized crystal structure parameters agree well with experimental values. The electronic structure shows that when Sn ions are doped in the host hexagonal WO3, Sn0.33WO3 displays a typical n-type electronic conductivity, which leads to an upshift of the Fermi energy to the conduction band. It was found that Sn0.33WO3 exhibits low reflectivity and weak absorption in the visible region, while exhibiting strong reflectivity and absorption in the near infrared light region. Therefore, it significantly reduces the optical transmittance of infrared wavelengths (down to 3.9% for the compacted film and 25.3% for the coated film), while maintaining fair optical transparency for visible wavelengths. This research indicates that Sn0.33WO3 is a prospective near infrared absorber and it can be used as near infrared shielding filters for smart windows with high transparency for visible light.

Highlights

The alkali-metal-doped hexagonal tungsten bronzes MxWO3 (M = Na,1K,1 Rb,2 Cs3,4) have received attention for their remarkable near infrared (NIR) absorption, which can be applied as a solar filter for smart-windows
There is a surge of interest to develop novel WO3based near infrared absorbing materials for solar filter applications to meet the high standards of energy saving and emission reduction in modern buildings and automobiles
The calculated density of states (DOS) for hexagonal WO3 (h-WO3) is not shown here but is in accordance with those obtained by Xu et al As can be seen from Fig. 3, the Fermi level is located at the bottommost conduction band and the W-5d state curve crosses the Fermi level after doping

Summary

INTRODUCTION

Yang et al. studied the electronic and optical properties of alkali metal monodoped and codoped h-WO3 using the firstprinciples hybrid density-functional HSE06 theory; the ratio (0.083) of alkali metal doped h-WO3 is significantly lower than the experimentally reported values of 0.15–0.33. Xu et al. presented a systematic theoretical investigation on the optical properties of Cs0.33WO3 using the DFT-GGA method, and the theoretical calculations are well carried out and there are good comparisons between the theoretical results and other practical experimental results. On this basis, we conclude that DFT-GGA calculations provide the best model fit for Sn-doped h-WO3. The solar radiation shielding performance of hexagonal Sn0.33WO3 films is predicted

COMPUTATIONAL DETAILS

Geometry structure

Electronic structures

Optical properties

CONCLUSIONS